diff --git a/include/swift/AST/DiagnosticsSema.def b/include/swift/AST/DiagnosticsSema.def
index ce3748ccff1..d7fb06863cc 100644
--- a/include/swift/AST/DiagnosticsSema.def
+++ b/include/swift/AST/DiagnosticsSema.def
@@ -5697,8 +5697,6 @@ ERROR(preconcurrency_not_inheritance_clause,none,
       "'preconcurrency' attribute only applies in inheritance clauses", ())
 ERROR(preconcurrency_not_existential,none,
       "'preconcurrency' attribute cannot apply to non-protocol type %0", (Type))
-ERROR(preconcurrency_attr_disabled,none,
-      "attribute requires '-enable-experimental-feature DynamicActorIsolation'", ())
 
 ERROR(redundant_any_in_existential,none,
        "redundant 'any' in type %0",
diff --git a/include/swift/Basic/Features.def b/include/swift/Basic/Features.def
index a3106b8a881..04ca235e12d 100644
--- a/include/swift/Basic/Features.def
+++ b/include/swift/Basic/Features.def
@@ -191,6 +191,7 @@ UPCOMING_FEATURE(GlobalConcurrency, 412, 6)
 UPCOMING_FEATURE(InferSendableFromCaptures, 418, 6)
 UPCOMING_FEATURE(ImplicitOpenExistentials, 352, 6)
 UPCOMING_FEATURE(RegionBasedIsolation, 414, 6)
+UPCOMING_FEATURE(DynamicActorIsolation, 423, 6)
 UPCOMING_FEATURE(MoveOnlyPartialConsumption, 429, 6)
 
 // Swift 7
@@ -354,11 +355,6 @@ EXPERIMENTAL_FEATURE(GroupActorErrors, true)
 // Allow for the 'transferring' keyword to be applied to arguments and results.
 EXPERIMENTAL_FEATURE(TransferringArgsAndResults, true)
 
-// Enable `@preconcurrency` attribute on protocol conformances and runtime checks
-// of actor isolation in @obj thunks and arguments of APIs that haven't yet adopted
-// strict concurrency checking.
-EXPERIMENTAL_FEATURE(DynamicActorIsolation, false)
-
 // Allow for `switch` of noncopyable values to be borrowing or consuming.
 EXPERIMENTAL_FEATURE(BorrowingSwitch, true)
 
diff --git a/include/swift/Basic/LangOptions.h b/include/swift/Basic/LangOptions.h
index ba3aac31b52..c2805ac1011 100644
--- a/include/swift/Basic/LangOptions.h
+++ b/include/swift/Basic/LangOptions.h
@@ -593,6 +593,9 @@ namespace swift {
     /// type-checking, SIL verification, and IR emission,
     bool BypassResilienceChecks = false;
 
+    /// Disables `DynamicActorIsolation` feature.
+    bool DisableDynamicActorIsolation = false;
+
     /// Whether or not to allow experimental features that are only available
     /// in "production".
 #ifdef NDEBUG
@@ -605,6 +608,11 @@ namespace swift {
       return ActiveConcurrencyModel == ConcurrencyModel::TaskToThread;
     }
 
+    bool isDynamicActorIsolationCheckingEnabled() const {
+      return !DisableDynamicActorIsolation &&
+             hasFeature(Feature::DynamicActorIsolation);
+    }
+
     LangOptions();
 
     /// Sets the target we are building for and updates platform conditions
diff --git a/include/swift/Option/Options.td b/include/swift/Option/Options.td
index c78a45cd567..3a03eac4e67 100644
--- a/include/swift/Option/Options.td
+++ b/include/swift/Option/Options.td
@@ -817,6 +817,11 @@ def disable_actor_data_race_checks :
   Flags<[FrontendOption, DoesNotAffectIncrementalBuild]>,
   HelpText<"Disable runtime checks for actor data races">;
 
+def disable_dynamic_actor_isolation :
+  Flag<["-"], "disable-dynamic-actor-isolation">,
+  Flags<[FrontendOption, DoesNotAffectIncrementalBuild]>,
+  HelpText<"Disable dynamic actor isolation checks">;
+
 def enable_bare_slash_regex : Flag<["-"], "enable-bare-slash-regex">,
   Flags<[FrontendOption, ModuleInterfaceOption]>,
   HelpText<"Enable the use of forward slash regular-expression literal syntax">;
diff --git a/lib/AST/FeatureSet.cpp b/lib/AST/FeatureSet.cpp
index bb4285e872c..412ffa1c8e6 100644
--- a/lib/AST/FeatureSet.cpp
+++ b/lib/AST/FeatureSet.cpp
@@ -645,29 +645,7 @@ static bool usesFeatureTransferringArgsAndResults(Decl *decl) {
   return false;
 }
 
-static bool usesFeatureDynamicActorIsolation(Decl *decl) {
-  auto usesPreconcurrencyConformance = [&](const InheritedTypes &inherited) {
-    return llvm::any_of(
-        inherited.getEntries(),
-        [](const InheritedEntry &entry) { return entry.isPreconcurrency(); });
-  };
-
-  if (auto *T = dyn_cast<TypeDecl>(decl))
-    return usesPreconcurrencyConformance(T->getInherited());
-
-  if (auto *E = dyn_cast<ExtensionDecl>(decl)) {
-    // If type has `@preconcurrency` conformance(s) all of its
-    // extensions have to be guarded by the flag too.
-    if (auto *T = dyn_cast<TypeDecl>(E->getExtendedNominal())) {
-      if (usesPreconcurrencyConformance(T->getInherited()))
-        return true;
-    }
-
-    return usesPreconcurrencyConformance(E->getInherited());
-  }
-
-  return false;
-}
+UNINTERESTING_FEATURE(DynamicActorIsolation)
 
 UNINTERESTING_FEATURE(BorrowingSwitch)
 
diff --git a/lib/Driver/ToolChains.cpp b/lib/Driver/ToolChains.cpp
index 55dfc877f98..a945f376fa3 100644
--- a/lib/Driver/ToolChains.cpp
+++ b/lib/Driver/ToolChains.cpp
@@ -264,6 +264,7 @@ void ToolChain::addCommonFrontendArgs(const OutputInfo &OI,
   inputArgs.AddLastArg(arguments,
                        options::OPT_enable_actor_data_race_checks,
                        options::OPT_disable_actor_data_race_checks);
+  inputArgs.AddLastArg(arguments, options::OPT_disable_dynamic_actor_isolation);
   inputArgs.AddLastArg(arguments, options::OPT_warn_concurrency);
   inputArgs.AddLastArg(arguments, options::OPT_strict_concurrency);
   inputArgs.AddAllArgs(arguments, options::OPT_enable_experimental_feature);
diff --git a/lib/Frontend/CompilerInvocation.cpp b/lib/Frontend/CompilerInvocation.cpp
index 4b1164d1bb9..131614559d3 100644
--- a/lib/Frontend/CompilerInvocation.cpp
+++ b/lib/Frontend/CompilerInvocation.cpp
@@ -1535,6 +1535,9 @@ static bool ParseLangArgs(LangOptions &Opts, ArgList &Args,
     }
   }
 
+  Opts.DisableDynamicActorIsolation |=
+      Args.hasArg(OPT_disable_dynamic_actor_isolation);
+
 #if SWIFT_ENABLE_EXPERIMENTAL_PARSER_VALIDATION
   /// Enable round trip parsing via the new swift parser unless it is disabled
   /// explicitly. The new Swift parser can have mismatches with C++ parser -
diff --git a/lib/SILGen/SILGenBridging.cpp b/lib/SILGen/SILGenBridging.cpp
index 2871f5739e6..4e9a64da089 100644
--- a/lib/SILGen/SILGenBridging.cpp
+++ b/lib/SILGen/SILGenBridging.cpp
@@ -1593,14 +1593,12 @@ void SILGenFunction::emitNativeToForeignThunk(SILDeclRef thunk) {
   loc.markAutoGenerated();
   Scope scope(Cleanups, CleanupLocation(loc));
 
-  bool emitExecutorPrecondition =
-      getASTContext().LangOpts.hasFeature(Feature::DynamicActorIsolation);
-
   std::optional<ActorIsolation> isolation;
   if (F.isAsync()) {
     if (thunk.hasDecl())
       isolation = getActorIsolation(thunk.getDecl());
-  } else if (emitExecutorPrecondition) {
+  } else if (getASTContext()
+                 .LangOpts.isDynamicActorIsolationCheckingEnabled()) {
     if (thunk.hasDecl()) {
       isolation = getActorIsolation(thunk.getDecl());
     } else if (auto globalActor = nativeInfo.FormalType->getGlobalActor()) {
diff --git a/lib/SILGen/SILGenPoly.cpp b/lib/SILGen/SILGenPoly.cpp
index 0117ee68873..724a6df3166 100644
--- a/lib/SILGen/SILGenPoly.cpp
+++ b/lib/SILGen/SILGenPoly.cpp
@@ -7021,7 +7021,10 @@ void SILGenFunction::emitProtocolWitness(
 
     if (!F.isAsync()) {
       assert(isPreconcurrency);
-      emitPreconditionCheckExpectedExecutor(loc, *enterIsolation, actorSelf);
+
+      if (getASTContext().LangOpts.isDynamicActorIsolationCheckingEnabled()) {
+        emitPreconditionCheckExpectedExecutor(loc, *enterIsolation, actorSelf);
+      }
     } else {
       emitHopToTargetActor(loc, enterIsolation, actorSelf);
     }
diff --git a/lib/Sema/CSApply.cpp b/lib/Sema/CSApply.cpp
index 2fe49c9baf5..7514b5dff06 100644
--- a/lib/Sema/CSApply.cpp
+++ b/lib/Sema/CSApply.cpp
@@ -7462,7 +7462,7 @@ Expr *ExprRewriter::coerceToType(Expr *expr, Type toType,
       }
     }
 
-    if (ctx.LangOpts.hasFeature(Feature::DynamicActorIsolation)) {
+    if (ctx.LangOpts.isDynamicActorIsolationCheckingEnabled()) {
       // Passing a synchronous global actor-isolated function value and
       // parameter that expects a synchronous non-isolated function type could
       // require a runtime check to ensure that function is always called in
diff --git a/lib/Sema/TypeCheckType.cpp b/lib/Sema/TypeCheckType.cpp
index 7dc7f1d7343..24f5b11590b 100644
--- a/lib/Sema/TypeCheckType.cpp
+++ b/lib/Sema/TypeCheckType.cpp
@@ -3317,28 +3317,21 @@ TypeResolver::resolveAttributedType(TypeRepr *repr, TypeResolutionOptions option
   }
 
   if (auto preconcurrencyAttr = claim<PreconcurrencyTypeAttr>(attrs)) {
-    auto &ctx = getASTContext();
-    if (ctx.LangOpts.hasFeature(Feature::DynamicActorIsolation)) {
-      if (ty->hasError())
-        return ty;
+    if (ty->hasError())
+      return ty;
 
-      if (!options.is(TypeResolverContext::Inherited) ||
-          getDeclContext()->getSelfProtocolDecl()) {
-        diagnoseInvalid(repr, preconcurrencyAttr->getAtLoc(),
-                        diag::preconcurrency_not_inheritance_clause);
-        ty = ErrorType::get(getASTContext());
-      } else if (!ty->isConstraintType()) {
-        diagnoseInvalid(repr, preconcurrencyAttr->getAtLoc(),
-                        diag::preconcurrency_not_existential, ty);
-        ty = ErrorType::get(getASTContext());
-      }
-
-      // Nothing to record in the type.
-    } else {
+    if (!options.is(TypeResolverContext::Inherited) ||
+        getDeclContext()->getSelfProtocolDecl()) {
       diagnoseInvalid(repr, preconcurrencyAttr->getAtLoc(),
-                      diag::preconcurrency_attr_disabled);
+                      diag::preconcurrency_not_inheritance_clause);
+      ty = ErrorType::get(getASTContext());
+    } else if (!ty->isConstraintType()) {
+      diagnoseInvalid(repr, preconcurrencyAttr->getAtLoc(),
+                      diag::preconcurrency_not_existential, ty);
       ty = ErrorType::get(getASTContext());
     }
+
+    // Nothing to record in the type.
   }
 
   if (auto retroactiveAttr = claim<RetroactiveTypeAttr>(attrs)) {
diff --git a/test/ClangImporter/preconcurrency_conformances.swift b/test/ClangImporter/preconcurrency_conformances.swift
index ddb22be9ef5..c4fc0a00992 100644
--- a/test/ClangImporter/preconcurrency_conformances.swift
+++ b/test/ClangImporter/preconcurrency_conformances.swift
@@ -1,9 +1,14 @@
-// RUN: %target-swift-frontend(mock-sdk: %clang-importer-sdk) -disable-availability-checking -enable-experimental-feature DynamicActorIsolation -emit-silgen %s | %FileCheck %s
+// RUN: %empty-directory(%t/src)
+// RUN: split-file %s %t/src
+
+// RUN: %target-swift-frontend(mock-sdk: %clang-importer-sdk) -disable-availability-checking -enable-upcoming-feature DynamicActorIsolation -emit-silgen -module-name preconcurrency_conformances %t/src/checks.swift | %FileCheck %t/src/checks.swift
+// RUN: %target-swift-frontend(mock-sdk: %clang-importer-sdk) -disable-availability-checking -swift-version 6 -disable-dynamic-actor-isolation -emit-silgen -module-name preconcurrency_conformances %t/src/checks_disabled.swift | %FileCheck %t/src/checks_disabled.swift
 
 // REQUIRES: asserts
 // REQUIRES: concurrency
 // REQUIRES: objc_interop
 
+//--- checks.swift
 import Foundation
 
 actor MyActor {
@@ -130,3 +135,77 @@ class Sub : Super {
 // CHECK-NEXT: [[EXEC:%.*]] = extract_executor [[MAIN_ACTOR]] : $MainActor
 // CHECK: [[PRECONDITION:%.*]] = function_ref @$ss22_checkExpectedExecutor14_filenameStart01_D6Length01_D7IsASCII5_line9_executoryBp_BwBi1_BwBetF : $@convention(thin) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, Builtin.Word, Builtin.Executor) -> ()
 // CHECK-NEXT: {{.*}} = apply [[PRECONDITION]]({{.*}}, [[EXEC]]) : $@convention(thin) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, Builtin.Word, Builtin.Executor) -> ()
+
+//--- checks_disabled.swift
+import Foundation
+
+actor MyActor {
+}
+
+@globalActor
+struct GlobalActor {
+  static let shared: MyActor = MyActor()
+}
+
+@objc protocol P {
+  var data: String? { get set }
+
+  init()
+  func test() -> String?
+}
+
+@MainActor
+final class K : @preconcurrency P {
+  var data: String? {
+    get { nil }
+    set {}
+  }
+
+  init() {}
+  @GlobalActor func test() -> String? { nil }
+}
+
+// @objc K.data.getter
+// CHECK-LABEL: sil private [thunk] [ossa] @$s27preconcurrency_conformances1KC4dataSSSgvgTo : $@convention(objc_method) (K) -> @autoreleased Optional<NSString>
+// CHECK-NOT: [[PRECONDITION:%.*]] = function_ref @$ss22_checkExpectedExecutor14_filenameStart01_D6Length01_D7IsASCII5_line9_executoryBp_BwBi1_BwBetF : $@convention(thin) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, Builtin.Word, Builtin.Executor) -> ()
+
+// @objc K.data.setter
+// CHECK-LABEL: sil private [thunk] [ossa] @$s27preconcurrency_conformances1KC4dataSSSgvsTo : $@convention(objc_method) (Optional<NSString>, K) -> ()
+// CHECK-NOT: [[PRECONDITION:%.*]] = function_ref @$ss22_checkExpectedExecutor14_filenameStart01_D6Length01_D7IsASCII5_line9_executoryBp_BwBi1_BwBetF : $@convention(thin) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, Builtin.Word, Builtin.Executor) -> ()
+
+// @objc K.init()
+// CHECK-LABEL: sil private [thunk] [ossa] @$s27preconcurrency_conformances1KCACycfcTo : $@convention(objc_method) (@owned K) -> @owned K
+// CHECK-NOT: [[PRECONDITION:%.*]] = function_ref @$ss22_checkExpectedExecutor14_filenameStart01_D6Length01_D7IsASCII5_line9_executoryBp_BwBi1_BwBetF : $@convention(thin) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, Builtin.Word, Builtin.Executor) -> ()
+
+// @objc K.test()
+// CHECK-LABEL: sil private [thunk] [ossa] @$s27preconcurrency_conformances1KC4testSSSgyFTo : $@convention(objc_method) (K) -> @autoreleased Optional<NSString>
+// CHECK-NOT: [[PRECONDITION:%.*]] = function_ref @$ss22_checkExpectedExecutor14_filenameStart01_D6Length01_D7IsASCII5_line9_executoryBp_BwBi1_BwBetF : $@convention(thin) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, Builtin.Word, Builtin.Executor) -> ()
+
+@MainActor
+class TestObjCMethod {
+  @objc func testImplicit() -> Int { 42 }
+
+  @GlobalActor
+  @objc func testExplicit() {}
+}
+
+// CHECK-LABEL: sil private [thunk] [ossa] @$s27preconcurrency_conformances14TestObjCMethodC12testImplicitSiyFTo : $@convention(objc_method) (TestObjCMethod) -> Int
+// CHECK-NOT: [[PRECONDITION:%.*]] = function_ref @$ss22_checkExpectedExecutor14_filenameStart01_D6Length01_D7IsASCII5_line9_executoryBp_BwBi1_BwBetF : $@convention(thin) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, Builtin.Word, Builtin.Executor) -> ()
+
+// CHECK-LABEL: sil private [thunk] [ossa] @$s27preconcurrency_conformances14TestObjCMethodC12testExplicityyFTo : $@convention(objc_method) (TestObjCMethod) -> ()
+// CHECK-NOT: [[PRECONDITION:%.*]] = function_ref @$ss22_checkExpectedExecutor14_filenameStart01_D6Length01_D7IsASCII5_line9_executoryBp_BwBi1_BwBetF : $@convention(thin) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, Builtin.Word, Builtin.Executor) -> ()
+
+@objcMembers
+class Super {
+  @MainActor func test() {}
+}
+
+class Sub : Super {
+  override func test() {}
+}
+
+// CHECK-LABEL: sil private [thunk] [ossa] @$s27preconcurrency_conformances5SuperC4testyyFTo : $@convention(objc_method) (Super) -> ()
+// CHECK-NOT: [[PRECONDITION:%.*]] = function_ref @$ss22_checkExpectedExecutor14_filenameStart01_D6Length01_D7IsASCII5_line9_executoryBp_BwBi1_BwBetF : $@convention(thin) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, Builtin.Word, Builtin.Executor) -> ()
+
+// CHECK-LABEL: sil private [thunk] [ossa] @$s27preconcurrency_conformances3SubC4testyyFTo : $@convention(objc_method) (Sub) -> ()
+// CHECK-NOT: [[PRECONDITION:%.*]] = function_ref @$ss22_checkExpectedExecutor14_filenameStart01_D6Length01_D7IsASCII5_line9_executoryBp_BwBi1_BwBetF : $@convention(thin) (Builtin.RawPointer, Builtin.Word, Builtin.Int1, Builtin.Word, Builtin.Executor) -> ()
diff --git a/test/Concurrency/dynamic_checks_for_func_refs_in_preconcurrency_apis.swift b/test/Concurrency/dynamic_checks_for_func_refs_in_preconcurrency_apis.swift
index 96b5043647f..4834d9ac236 100644
--- a/test/Concurrency/dynamic_checks_for_func_refs_in_preconcurrency_apis.swift
+++ b/test/Concurrency/dynamic_checks_for_func_refs_in_preconcurrency_apis.swift
@@ -12,7 +12,7 @@
 // RUN:   -I %t \
 // RUN:   -disable-availability-checking \
 // RUN:   -module-name Client \
-// RUN:   -enable-experimental-feature DynamicActorIsolation \
+// RUN:   -enable-upcoming-feature DynamicActorIsolation \
 // RUN:    %t/src/Client.swift -verify | %FileCheck %s
 
 // Delete swiftmodule to test building against swiftinterface
@@ -23,7 +23,7 @@
 // RUN:   -I %t \
 // RUN:   -disable-availability-checking \
 // RUN:   -module-name Client \
-// RUN:   -enable-experimental-feature DynamicActorIsolation \
+// RUN:   -enable-upcoming-feature DynamicActorIsolation \
 // RUN:    %t/src/Client.swift -verify | %FileCheck %s
 
 // REQUIRES: asserts
diff --git a/test/Concurrency/dynamic_checks_for_func_refs_in_preconcurrency_apis_objc.swift b/test/Concurrency/dynamic_checks_for_func_refs_in_preconcurrency_apis_objc.swift
index 1601a520826..16c14a6e90d 100644
--- a/test/Concurrency/dynamic_checks_for_func_refs_in_preconcurrency_apis_objc.swift
+++ b/test/Concurrency/dynamic_checks_for_func_refs_in_preconcurrency_apis_objc.swift
@@ -1,4 +1,4 @@
-// RUN: %target-swift-frontend(mock-sdk: %clang-importer-sdk) -target arm64-apple-macosx10.15 -enable-experimental-feature DynamicActorIsolation -emit-silgen -verify %s | %FileCheck %s
+// RUN: %target-swift-frontend(mock-sdk: %clang-importer-sdk) -target arm64-apple-macosx10.15 -enable-upcoming-feature DynamicActorIsolation -emit-silgen -verify %s | %FileCheck %s
 // REQUIRES: objc_interop
 // REQUIRES: asserts
 
diff --git a/test/Concurrency/preconcurrency_conformances.swift b/test/Concurrency/preconcurrency_conformances.swift
index ce544948023..78d4b5e231e 100644
--- a/test/Concurrency/preconcurrency_conformances.swift
+++ b/test/Concurrency/preconcurrency_conformances.swift
@@ -1,4 +1,4 @@
-// RUN: %target-swift-frontend -swift-version 5 -disable-availability-checking %s -emit-sil -o /dev/null -verify -enable-experimental-feature DynamicActorIsolation -strict-concurrency=complete -verify-additional-prefix complete-tns-
+// RUN: %target-swift-frontend -swift-version 5 -disable-availability-checking %s -emit-sil -o /dev/null -verify -enable-upcoming-feature DynamicActorIsolation -strict-concurrency=complete -verify-additional-prefix complete-tns-
 
 // REQUIRES: concurrency
 // REQUIRES: asserts
diff --git a/test/Interpreter/preconcurrency_conformances.swift b/test/Interpreter/preconcurrency_conformances.swift
index b8cd33c8ffb..efe7c2e18f0 100644
--- a/test/Interpreter/preconcurrency_conformances.swift
+++ b/test/Interpreter/preconcurrency_conformances.swift
@@ -12,21 +12,21 @@
 // RUN:    -target %target-cpu-apple-macosx10.15 \
 // RUN:    -I %t -L %t -l Interface \
 // RUN:    -emit-module-interface-path %t/Types.swiftinterface \
-// RUN:    -Xfrontend -enable-experimental-feature -Xfrontend DynamicActorIsolation
+// RUN:    -Xfrontend -enable-upcoming-feature -Xfrontend DynamicActorIsolation
 
-// RUN: %target-build-swift -Xfrontend -enable-experimental-feature -Xfrontend DynamicActorIsolation -I %t -L %t -l Types %t/src/Crash1.swift -o %t/crash1.out
+// RUN: %target-build-swift -Xfrontend -enable-upcoming-feature -Xfrontend DynamicActorIsolation -I %t -L %t -l Types %t/src/Crash1.swift -o %t/crash1.out
 // RUN: %target-codesign %t/crash1.out
 // RUN: not --crash env SWIFT_UNEXPECTED_EXECUTOR_LOG_LEVEL=2 %target-run %t/crash1.out 2>&1 | %FileCheck %t/src/Crash1.swift
 
-// RUN: %target-build-swift -Xfrontend -enable-experimental-feature -Xfrontend DynamicActorIsolation -I %t -L %t -l Types %t/src/Crash2.swift -o %t/crash2.out
+// RUN: %target-build-swift -Xfrontend -enable-upcoming-feature -Xfrontend DynamicActorIsolation -I %t -L %t -l Types %t/src/Crash2.swift -o %t/crash2.out
 // RUN: %target-codesign %t/crash2.out
 // RUN: not --crash env SWIFT_UNEXPECTED_EXECUTOR_LOG_LEVEL=2 %target-run %t/crash2.out 2>&1 | %FileCheck %t/src/Crash2.swift
 
-// RUN: %target-build-swift -Xfrontend -enable-experimental-feature -Xfrontend DynamicActorIsolation -I %t -L %t -l Types %t/src/Crash3.swift -o %t/crash3.out
+// RUN: %target-build-swift -Xfrontend -enable-upcoming-feature -Xfrontend DynamicActorIsolation -I %t -L %t -l Types %t/src/Crash3.swift -o %t/crash3.out
 // RUN: %target-codesign %t/crash3.out
 // RUN: not --crash env SWIFT_UNEXPECTED_EXECUTOR_LOG_LEVEL=2 %target-run %t/crash3.out 2>&1 | %FileCheck %t/src/Crash3.swift
 
-// RUN: %target-build-swift -Xfrontend -enable-experimental-feature -Xfrontend DynamicActorIsolation -I %t -L %t -l Types %t/src/Crash4.swift -o %t/crash4.out
+// RUN: %target-build-swift -Xfrontend -enable-upcoming-feature -Xfrontend DynamicActorIsolation -I %t -L %t -l Types %t/src/Crash4.swift -o %t/crash4.out
 // RUN: %target-codesign %t/crash4.out
 // RUN: not --crash env SWIFT_UNEXPECTED_EXECUTOR_LOG_LEVEL=2 %target-run %t/crash4.out 2>&1 | %FileCheck %t/src/Crash4.swift
 
diff --git a/test/Interpreter/preconcurrency_conformances_with_disabled_checks.swift b/test/Interpreter/preconcurrency_conformances_with_disabled_checks.swift
new file mode 100644
index 00000000000..911daa27a22
--- /dev/null
+++ b/test/Interpreter/preconcurrency_conformances_with_disabled_checks.swift
@@ -0,0 +1,105 @@
+// RUN: %empty-directory(%t/src)
+// RUN: split-file %s %t/src
+
+// RUN: %target-build-swift %t/src/Interface.swift -emit-module -emit-library \
+// RUN:    -target %target-cpu-apple-macosx10.15 -swift-version 5 \
+// RUN:    -enable-library-evolution \
+// RUN:    -module-name Interface \
+// RUN:    -o %t/%target-library-name(Interface) \
+// RUN:    -emit-module-interface-path %t/Interface.swiftinterface
+
+// RUN: %target-build-swift %t/src/Types.swift -swift-version 5 -emit-module -emit-library -enable-library-evolution -module-name Types -o %t/%target-library-name(Types) \
+// RUN:    -target %target-cpu-apple-macosx10.15 \
+// RUN:    -I %t -L %t -l Interface \
+// RUN:    -emit-module-interface-path %t/Types.swiftinterface \
+// RUN:    -Xfrontend -enable-upcoming-feature -Xfrontend DynamicActorIsolation \
+// RUN:    -Xfrontend -disable-dynamic-actor-isolation
+
+// RUN: %target-build-swift -I %t -L %t -l Types %t/src/Test1.swift -o %t/test1.out
+// RUN: %target-codesign %t/test1.out
+// RUN: env SWIFT_UNEXPECTED_EXECUTOR_LOG_LEVEL=2 %target-run %t/test1.out 2>&1 | %FileCheck %t/src/Test1.swift
+
+// RUN: %target-build-swift -I %t -L %t -l Types %t/src/Test2.swift -o %t/test2.out
+// RUN: %target-codesign %t/test2.out
+// RUN: env SWIFT_UNEXPECTED_EXECUTOR_LOG_LEVEL=2 %target-run %t/test2.out 2>&1 | %FileCheck %t/src/Test2.swift
+
+// RUN: %target-build-swift -I %t -L %t -l Types %t/src/Test3.swift -o %t/test3.out
+// RUN: %target-codesign %t/test3.out
+// RUN: env SWIFT_UNEXPECTED_EXECUTOR_LOG_LEVEL=2 %target-run %t/test3.out 2>&1 | %FileCheck %t/src/Test3.swift
+
+// RUN: %target-build-swift -I %t -L %t -l Types %t/src/Test4.swift -o %t/test4.out
+// RUN: %target-codesign %t/test4.out
+// RUN: env SWIFT_UNEXPECTED_EXECUTOR_LOG_LEVEL=2 %target-run %t/test4.out 2>&1 | %FileCheck %t/src/Test4.swift
+
+// REQUIRES: asserts
+// REQUIRES: concurrency
+// REQUIRES: concurrency_runtime
+// REQUIRES: executable_test
+// REQUIRES: OS=macosx
+
+// rdar://123810657
+// UNSUPPORTED: back_deployment_runtime
+
+//--- Interface.swift
+public protocol P {
+  init()
+
+  var prop: [String] { get set }
+  func test() -> Int
+}
+
+//--- Types.swift
+import Interface
+
+public func runTest<T: P>(_ type: T.Type) async -> Int {
+  let v = type.init()
+  return v.test()
+}
+
+public func runAccessors<T: P>(_ type: T.Type) async -> [String] {
+  var v = type.init()
+  v.prop = ["a", "b", "c"]
+  return v.prop
+}
+
+public final class Test : @preconcurrency P {
+  @MainActor public var prop: [String] = []
+  @MainActor public func test() -> Int { 42 }
+
+  public init() {}
+}
+
+public actor ActorTest {
+  var x: Int = 0
+
+  public init() {}
+}
+
+extension ActorTest : @preconcurrency P {
+  public var prop: [String] {
+    get { [] }
+    set { }
+  }
+
+  public func test() -> Int { x }
+}
+
+//--- Test1.swift
+import Types
+print(await runTest(Test.self))
+// CHECK-NOT: Incorrect actor executor assumption; Expected MainActor executor
+
+//--- Test2.swift
+import Types
+print(await runAccessors(Test.self))
+// CHECK-NOT: Incorrect actor executor assumption; Expected MainActor executor
+
+//--- Test3.swift
+import Types
+print(await runTest(ActorTest.self))
+// CHECK-NOT: Incorrect actor executor assumption
+
+//--- Test4.swift
+import Types
+print(await runAccessors(ActorTest.self))
+// CHECK-NOT: Incorrect actor executor assumption
diff --git a/test/ModuleInterface/preconcurrency_conformances.swift b/test/ModuleInterface/preconcurrency_conformances.swift
index 459afd610b4..0b0900ae5af 100644
--- a/test/ModuleInterface/preconcurrency_conformances.swift
+++ b/test/ModuleInterface/preconcurrency_conformances.swift
@@ -12,17 +12,17 @@
 // RUN:   -module-name Client -I %t -swift-version 5 -enable-library-evolution \
 // RUN:   -emit-module-path %t/Client.swiftmodule \
 // RUN:   -emit-module-interface-path %t/Client.swiftinterface \
-// RUN:   -enable-experimental-feature DynamicActorIsolation \
+// RUN:   -enable-upcoming-feature DynamicActorIsolation \
 // RUN:   -disable-availability-checking \
 // RUN:   -verify
 
 // RUN: %FileCheck %s < %t/Client.swiftinterface
 
 // RUN: %target-swift-emit-module-interface(%t/Client.swiftinterface) -I %t %t/src/Client.swift -module-name Client \
-// RUN:   -disable-availability-checking -enable-experimental-feature DynamicActorIsolation -verify
+// RUN:   -disable-availability-checking -enable-upcoming-feature DynamicActorIsolation -verify
 
 // RUN: %target-swift-typecheck-module-from-interface(%t/Client.swiftinterface) -I %t -module-name Client \
-// RUN:   -disable-availability-checking -enable-experimental-feature DynamicActorIsolation -verify
+// RUN:   -disable-availability-checking -enable-upcoming-feature DynamicActorIsolation -verify
 
 // REQUIRES: asserts
 // REQUIRES: concurrency
@@ -44,8 +44,8 @@ public protocol WithAssoc {
 //--- Client.swift
 import A
 
-// CHECK: #if {{.*}} $DynamicActorIsolation
-// CHECK-NEXT: @_Concurrency.MainActor public struct GlobalActorTest : @preconcurrency A.P
+// CHECK-NOT: #if {{.*}} $DynamicActorIsolation
+// CHECK: @_Concurrency.MainActor public struct GlobalActorTest : @preconcurrency A.P
 
 @MainActor
 public struct GlobalActorTest : @preconcurrency P {
@@ -56,14 +56,14 @@ public struct GlobalActorTest : @preconcurrency P {
 public class ExtTest {
 }
 
-// CHECK: #if {{.*}} $DynamicActorIsolation
-// CHECK-NEXT: extension Client.ExtTest : @preconcurrency A.P
+// CHECK-NOT: #if {{.*}} $DynamicActorIsolation
+// CHECK: extension Client.ExtTest : @preconcurrency A.P
 extension ExtTest : @preconcurrency P {
   public func test() -> Int { 1 }
 }
 
-// CHECK: #if {{.*}} && $DynamicActorIsolation
-// CHECK-NEXT: public actor ActorTest : @preconcurrency A.P
+// CHECK-NOT: #if {{.*}} && $DynamicActorIsolation
+// CHECK: public actor ActorTest : @preconcurrency A.P
 public actor ActorTest : @preconcurrency P {
   public func test() -> Int { 2 }
 }
@@ -71,22 +71,21 @@ public actor ActorTest : @preconcurrency P {
 public actor ActorExtTest {
 }
 
-// CHECK: #if {{.*}} $DynamicActorIsolation
-// CHECK-NEXT: extension Client.ActorExtTest : @preconcurrency A.Q
+// CHECK-NOT: #if {{.*}} $DynamicActorIsolation
+// CHECK: extension Client.ActorExtTest : @preconcurrency A.Q
 extension ActorExtTest : @preconcurrency Q {
   public var x: Int { 42 }
 }
 
 public struct TestConditional<T> {}
 
-// CHECK: #if {{.*}} $DynamicActorIsolation
-// CHECK-NEXT: extension Client.TestConditional : @preconcurrency A.WithAssoc where T == Swift.Int {
+// CHECK-NOT: #if {{.*}} $DynamicActorIsolation
+// CHECK: extension Client.TestConditional : @preconcurrency A.WithAssoc where T == Swift.Int {
 // CHECK-NEXT:  @_Concurrency.MainActor public func test() -> T
 // CHECK-NEXT: }
 extension TestConditional : @preconcurrency WithAssoc where T == Int {
   @MainActor public func test() -> T { 42 } // Ok
 }
 
-// CHECK: #if {{.*}} $DynamicActorIsolation
-// CHECK-NEXT: extension Client.GlobalActorTest : Swift.Sendable {}
-// CHECK-NEXT: #endif
+// CHECK-NOT: #if {{.*}} $DynamicActorIsolation
+// CHECK: extension Client.GlobalActorTest : Swift.Sendable {}
diff --git a/test/SILGen/preconcurrency_conformances.swift b/test/SILGen/preconcurrency_conformances.swift
index a4afe72d209..e1c47378ca6 100644
--- a/test/SILGen/preconcurrency_conformances.swift
+++ b/test/SILGen/preconcurrency_conformances.swift
@@ -1,8 +1,13 @@
-// RUN: %target-swift-emit-silgen -disable-availability-checking -module-name preconcurrency_conformances -enable-experimental-feature DynamicActorIsolation %s -verify | %FileCheck %s
+// RUN: %empty-directory(%t/src)
+// RUN: split-file %s %t/src
+
+// RUN: %target-swift-emit-silgen -disable-availability-checking -module-name preconcurrency_conformances -enable-upcoming-feature DynamicActorIsolation %t/src/checks.swift -verify | %FileCheck %t/src/checks.swift
+// RUN: %target-swift-emit-silgen -swift-version 6 -disable-availability-checking -module-name preconcurrency_conformances -disable-dynamic-actor-isolation %t/src/checks_disabled.swift -verify | %FileCheck %t/src/checks_disabled.swift
 
 // REQUIRES: asserts
 // REQUIRES: concurrency
 
+//--- checks.swift
 protocol P {
   associatedtype T
 
@@ -270,3 +275,167 @@ extension MyActor : @preconcurrency Q {
 // CHECK-NEXT: [[EXEC:%.*]] = extract_executor [[MAIN_ACTOR]] : $MainActor
 // CHECK: [[CHECK_EXEC_REF:%.*]] = function_ref @$ss22_checkExpectedExecutor14_filenameStart01_D6Length01_D7IsASCII5_line9_executoryBp_BwBi1_BwBetF
 // CHECK-NEXT: {{.*}} = apply [[CHECK_EXEC_REF]]({{.*}}, [[EXEC]])
+
+//--- checks_disabled.swift
+protocol P {
+  associatedtype T
+
+  var prop: T { get set }
+  func fn() -> T?
+}
+
+protocol Q {
+  static var data: [Int]? { get set }
+  static func staticFn() -> String?
+}
+
+actor MyActor {
+}
+
+@globalActor
+struct GlobalActor {
+  static let shared: MyActor = MyActor()
+}
+
+@MainActor
+struct IsolatedType<T: Sendable> : @preconcurrency P {
+  var prop: T
+  func fn() -> T? { nil }
+}
+
+// protocol witness for P.prop.getter in conformance IsolatedType<A>
+// CHECK-LABEL: sil private [transparent] [thunk] [ossa] @$s27preconcurrency_conformances12IsolatedTypeVyxGAA1PA2aEP4prop1TQzvgTW : $@convention(witness_method: P) <τ_0_0 where τ_0_0 : Sendable> (@in_guaranteed IsolatedType<τ_0_0>) -> @out τ_0_0
+// CHECK-NOT: [[CHECK_EXEC_REF:%.*]] = function_ref @$ss22_checkExpectedExecutor14_filenameStart01_D6Length01_D7IsASCII5_line9_executoryBp_BwBi1_BwBetF
+
+// protocol witness for P.prop.setter in conformance IsolatedType<A>
+// CHECK-LABEL: sil private [transparent] [thunk] [ossa] @$s27preconcurrency_conformances12IsolatedTypeVyxGAA1PA2aEP4prop1TQzvsTW : $@convention(witness_method: P) <τ_0_0 where τ_0_0 : Sendable> (@in τ_0_0, @inout IsolatedType<τ_0_0>) -> ()
+// CHECK-NOT: [[CHECK_EXEC_REF:%.*]] = function_ref @$ss22_checkExpectedExecutor14_filenameStart01_D6Length01_D7IsASCII5_line9_executoryBp_BwBi1_BwBetF
+
+// protocol witness for P.prop.modify in conformance IsolatedType<A>
+// CHECK-LABEL: sil private [transparent] [thunk] [ossa] @$s27preconcurrency_conformances12IsolatedTypeVyxGAA1PA2aEP4prop1TQzvMTW : $@yield_once @convention(witness_method: P) <τ_0_0 where τ_0_0 : Sendable> @substituted <τ_0_0, τ_0_1> (@inout τ_0_0) -> @yields @inout τ_0_1 for <IsolatedType<τ_0_0>, τ_0_0>
+// CHECK-NOT: [[CHECK_EXEC_REF:%.*]] = function_ref @$ss22_checkExpectedExecutor14_filenameStart01_D6Length01_D7IsASCII5_line9_executoryBp_BwBi1_BwBetF
+
+// protocol witness for P.fn() in conformance IsolatedType<A>
+// CHECK-LABEL: sil private [transparent] [thunk] [ossa] @$s27preconcurrency_conformances12IsolatedTypeVyxGAA1PA2aEP2fn1TQzSgyFTW : $@convention(witness_method: P) <τ_0_0 where τ_0_0 : Sendable> (@in_guaranteed IsolatedType<τ_0_0>) -> @out Optional<τ_0_0>
+// CHECK-NOT: [[CHECK_EXEC_REF:%.*]] = function_ref @$ss22_checkExpectedExecutor14_filenameStart01_D6Length01_D7IsASCII5_line9_executoryBp_BwBi1_BwBetF
+
+extension IsolatedType : @preconcurrency Q {
+  static var data: [Int]? {
+    get { nil }
+    set {}
+  }
+
+  static func staticFn() -> String? { nil }
+}
+
+// protocol witness for static Q.data.getter in conformance IsolatedType<A>
+// CHECK-LABEL: sil private [transparent] [thunk] [ossa] @$s27preconcurrency_conformances12IsolatedTypeVyxGAA1QA2aEP4dataSaySiGSgvgZTW : $@convention(witness_method: Q) <τ_0_0 where τ_0_0 : Sendable> (@thick IsolatedType<τ_0_0>.Type) -> @owned Optional<Array<Int>>
+// CHECK-NOT: [[CHECK_EXEC_REF:%.*]] = function_ref @$ss22_checkExpectedExecutor14_filenameStart01_D6Length01_D7IsASCII5_line9_executoryBp_BwBi1_BwBetF
+
+// protocol witness for static Q.data.setter in conformance IsolatedType<A>
+// CHECK-LABEL: sil private [transparent] [thunk] [ossa] @$s27preconcurrency_conformances12IsolatedTypeVyxGAA1QA2aEP4dataSaySiGSgvsZTW : $@convention(witness_method: Q) <τ_0_0 where τ_0_0 : Sendable> (@owned Optional<Array<Int>>, @thick IsolatedType<τ_0_0>.Type) -> ()
+// CHECK-NOT: [[CHECK_EXEC_REF:%.*]] = function_ref @$ss22_checkExpectedExecutor14_filenameStart01_D6Length01_D7IsASCII5_line9_executoryBp_BwBi1_BwBetF
+
+// protocol witness for static Q.data.modify in conformance IsolatedType<A>
+// CHECK-LABEL: sil private [transparent] [thunk] [ossa] @$s27preconcurrency_conformances12IsolatedTypeVyxGAA1QA2aEP4dataSaySiGSgvMZTW : $@yield_once @convention(witness_method: Q) <τ_0_0 where τ_0_0 : Sendable> @substituted <τ_0_0> (@thick τ_0_0.Type) -> @yields @inout Optional<Array<Int>> for <IsolatedType<τ_0_0>>
+// CHECK-NOT: [[CHECK_EXEC_REF:%.*]] = function_ref @$ss22_checkExpectedExecutor14_filenameStart01_D6Length01_D7IsASCII5_line9_executoryBp_BwBi1_BwBetF
+
+// protocol witness for static Q.staticFn() in conformance IsolatedType<A>
+// CHECK-LABEL: sil private [transparent] [thunk] [ossa] @$s27preconcurrency_conformances12IsolatedTypeVyxGAA1QA2aEP8staticFnSSSgyFZTW : $@convention(witness_method: Q) <τ_0_0 where τ_0_0 : Sendable> (@thick IsolatedType<τ_0_0>.Type) -> @owned Optional<String>
+// CHECK-NOT: [[CHECK_EXEC_REF:%.*]] = function_ref @$ss22_checkExpectedExecutor14_filenameStart01_D6Length01_D7IsASCII5_line9_executoryBp_BwBi1_BwBetF
+
+class IsolatedMembers<T: Sendable> : @preconcurrency P {
+  @MainActor var prop: T {
+    get { fatalError() }
+    set {}
+  }
+
+  @GlobalActor func fn() -> T? { nil }
+}
+
+// protocol witness for P.prop.getter in conformance IsolatedMembers<A>
+// CHECK-LABEL: sil private [transparent] [thunk] [ossa] @$s27preconcurrency_conformances15IsolatedMembersCyxGAA1PA2aEP4prop1TQzvgTW : $@convention(witness_method: P) <τ_0_0 where τ_0_0 : Sendable> (@in_guaranteed IsolatedMembers<τ_0_0>) -> @out τ_0_0
+// CHECK-NOT: [[CHECK_EXEC_REF:%.*]] = function_ref @$ss22_checkExpectedExecutor14_filenameStart01_D6Length01_D7IsASCII5_line9_executoryBp_BwBi1_BwBetF
+
+// protocol witness for P.prop.setter in conformance IsolatedMembers<A>
+// CHECK-LABEL: sil private [transparent] [thunk] [ossa] @$s27preconcurrency_conformances15IsolatedMembersCyxGAA1PA2aEP4prop1TQzvsTW : $@convention(witness_method: P) <τ_0_0 where τ_0_0 : Sendable> (@in τ_0_0, @inout IsolatedMembers<τ_0_0>) -> ()
+// CHECK-NOT: [[CHECK_EXEC_REF:%.*]] = function_ref @$ss22_checkExpectedExecutor14_filenameStart01_D6Length01_D7IsASCII5_line9_executoryBp_BwBi1_BwBetF
+
+// protocol witness for P.prop.modify in conformance IsolatedMembers<A>
+// CHECK-LABEL: sil private [transparent] [thunk] [ossa] @$s27preconcurrency_conformances15IsolatedMembersCyxGAA1PA2aEP4prop1TQzvMTW : $@yield_once @convention(witness_method: P) <τ_0_0 where τ_0_0 : Sendable> @substituted <τ_0_0, τ_0_1> (@inout τ_0_0) -> @yields @inout τ_0_1 for <IsolatedMembers<τ_0_0>, τ_0_0>
+// CHECK-NOT: [[CHECK_EXEC_REF:%.*]] = function_ref @$ss22_checkExpectedExecutor14_filenameStart01_D6Length01_D7IsASCII5_line9_executoryBp_BwBi1_BwBetF
+
+// protocol witness for P.fn() in conformance IsolatedMembers<A>
+// CHECK-LABEL: sil private [transparent] [thunk] [ossa] @$s27preconcurrency_conformances15IsolatedMembersCyxGAA1PA2aEP2fn1TQzSgyFTW : $@convention(witness_method: P) <τ_0_0 where τ_0_0 : Sendable> (@in_guaranteed IsolatedMembers<τ_0_0>) -> @out Optional<τ_0_0>
+// CHECK-NOT: [[CHECK_EXEC_REF:%.*]] = function_ref @$ss22_checkExpectedExecutor14_filenameStart01_D6Length01_D7IsASCII5_line9_executoryBp_BwBi1_BwBetF
+
+extension IsolatedMembers : @preconcurrency Q {
+  @GlobalActor static var data: [Int]? {
+    get { nil }
+    set {}
+  }
+
+  @MainActor static func staticFn() -> String? { nil }
+}
+
+// protocol witness for static Q.data.getter in conformance IsolatedMembers<A>
+// CHECK-LABEL: sil private [transparent] [thunk] [ossa] @$s27preconcurrency_conformances15IsolatedMembersCyxGAA1QA2aEP4dataSaySiGSgvgZTW : $@convention(witness_method: Q) <τ_0_0 where τ_0_0 : Sendable> (@thick IsolatedMembers<τ_0_0>.Type) -> @owned Optional<Array<Int>>
+// CHECK-NOT: [[CHECK_EXEC_REF:%.*]] = function_ref @$ss22_checkExpectedExecutor14_filenameStart01_D6Length01_D7IsASCII5_line9_executoryBp_BwBi1_BwBetF
+
+// protocol witness for static Q.data.setter in conformance IsolatedMembers<A>
+// CHECK-LABEL: sil private [transparent] [thunk] [ossa] @$s27preconcurrency_conformances15IsolatedMembersCyxGAA1QA2aEP4dataSaySiGSgvsZTW : $@convention(witness_method: Q) <τ_0_0 where τ_0_0 : Sendable> (@owned Optional<Array<Int>>, @thick IsolatedMembers<τ_0_0>.Type) -> ()
+// CHECK-NOT: [[CHECK_EXEC_REF:%.*]] = function_ref @$ss22_checkExpectedExecutor14_filenameStart01_D6Length01_D7IsASCII5_line9_executoryBp_BwBi1_BwBetF
+
+// protocol witness for static Q.data.modify in conformance IsolatedMembers<A>
+// CHECK-LABEL: sil private [transparent] [thunk] [ossa] @$s27preconcurrency_conformances15IsolatedMembersCyxGAA1QA2aEP4dataSaySiGSgvMZTW : $@yield_once @convention(witness_method: Q) <τ_0_0 where τ_0_0 : Sendable> @substituted <τ_0_0> (@thick τ_0_0.Type) -> @yields @inout Optional<Array<Int>> for <IsolatedMembers<τ_0_0>>
+// CHECK-NOT: [[CHECK_EXEC_REF:%.*]] = function_ref @$ss22_checkExpectedExecutor14_filenameStart01_D6Length01_D7IsASCII5_line9_executoryBp_BwBi1_BwBetF
+
+// protocol witness for static Q.staticFn() in conformance IsolatedMembers<A>
+// CHECK-LABEL: sil private [transparent] [thunk] [ossa] @$s27preconcurrency_conformances15IsolatedMembersCyxGAA1QA2aEP8staticFnSSSgyFZTW : $@convention(witness_method: Q) <τ_0_0 where τ_0_0 : Sendable> (@thick IsolatedMembers<τ_0_0>.Type) -> @owned Optional<String>
+// CHECK-NOT: [[CHECK_EXEC_REF:%.*]] = function_ref @$ss22_checkExpectedExecutor14_filenameStart01_D6Length01_D7IsASCII5_line9_executoryBp_BwBi1_BwBetF
+
+extension MyActor : @preconcurrency P {
+  var prop: Int {
+    get { 42 }
+    set {}
+  }
+
+  func fn() -> Int? { nil }
+}
+
+// protocol witness for P.prop.getter in conformance MyActor
+// CHECK-LABEL: sil private [transparent] [thunk] [ossa] @$s27preconcurrency_conformances7MyActorCAA1PA2aDP4prop1TQzvgTW : $@convention(witness_method: P) (@in_guaranteed MyActor) -> @out Int
+// CHECK-NOT: [[CHECK_EXEC_REF:%.*]] = function_ref @$ss22_checkExpectedExecutor14_filenameStart01_D6Length01_D7IsASCII5_line9_executoryBp_BwBi1_BwBetF
+
+// protocol witness for P.prop.setter in conformance MyActor
+// CHECK-LABEL: sil private [transparent] [thunk] [ossa] @$s27preconcurrency_conformances7MyActorCAA1PA2aDP4prop1TQzvsTW : $@convention(witness_method: P) (@in Int, @inout MyActor) -> ()
+// CHECK-NOT: [[CHECK_EXEC_REF:%.*]] = function_ref @$ss22_checkExpectedExecutor14_filenameStart01_D6Length01_D7IsASCII5_line9_executoryBp_BwBi1_BwBetF
+
+// protocol witness for P.prop.modify in conformance MyActor
+// CHECK-LABEL: sil private [transparent] [thunk] [ossa] @$s27preconcurrency_conformances7MyActorCAA1PA2aDP4prop1TQzvMTW : $@yield_once @convention(witness_method: P) @substituted <τ_0_0, τ_0_1> (@inout τ_0_0) -> @yields @inout τ_0_1 for <MyActor, Int>
+// CHECK-NOT: [[CHECK_EXEC_REF:%.*]] = function_ref @$ss22_checkExpectedExecutor14_filenameStart01_D6Length01_D7IsASCII5_line9_executoryBp_BwBi1_BwBetF
+
+// protocol witness for P.fn() in conformance MyActor
+// CHECK-LABEL: sil private [transparent] [thunk] [ossa] @$s27preconcurrency_conformances7MyActorCAA1PA2aDP2fn1TQzSgyFTW : $@convention(witness_method: P) (@in_guaranteed MyActor) -> @out Optional<Int>
+// CHECK-NOT: [[CHECK_EXEC_REF:%.*]] = function_ref @$ss22_checkExpectedExecutor14_filenameStart01_D6Length01_D7IsASCII5_line9_executoryBp_BwBi1_BwBetF
+
+extension MyActor : @preconcurrency Q {
+  @MainActor static var data: [Int]? {
+    get { nil }
+    set {}
+  }
+
+  @MainActor static func staticFn() -> String? { nil }
+}
+
+// protocol witness for static Q.data.getter in conformance MyActor
+// CHECK-LABEL: sil private [transparent] [thunk] [ossa] @$s27preconcurrency_conformances7MyActorCAA1QA2aDP4dataSaySiGSgvgZTW : $@convention(witness_method: Q) (@thick MyActor.Type) -> @owned Optional<Array<Int>>
+// CHECK-NOT: [[CHECK_EXEC_REF:%.*]] = function_ref @$ss22_checkExpectedExecutor14_filenameStart01_D6Length01_D7IsASCII5_line9_executoryBp_BwBi1_BwBetF
+
+// protocol witness for static Q.data.setter in conformance MyActor
+// CHECK-LABEL: sil private [transparent] [thunk] [ossa] @$s27preconcurrency_conformances7MyActorCAA1QA2aDP4dataSaySiGSgvsZTW : $@convention(witness_method: Q) (@owned Optional<Array<Int>>, @thick MyActor.Type) -> ()
+// CHECK-NOT: [[CHECK_EXEC_REF:%.*]] = function_ref @$ss22_checkExpectedExecutor14_filenameStart01_D6Length01_D7IsASCII5_line9_executoryBp_BwBi1_BwBetF
+
+// protocol witness for static Q.data.modify in conformance MyActor
+// CHECK-LABEL: sil private [transparent] [thunk] [ossa] @$s27preconcurrency_conformances7MyActorCAA1QA2aDP4dataSaySiGSgvMZTW : $@yield_once @convention(witness_method: Q) @substituted <τ_0_0> (@thick τ_0_0.Type) -> @yields @inout Optional<Array<Int>> for <MyActor>
+// CHECK-NOT: [[CHECK_EXEC_REF:%.*]] = function_ref @$ss22_checkExpectedExecutor14_filenameStart01_D6Length01_D7IsASCII5_line9_executoryBp_BwBi1_BwBetF
diff --git a/test/SILGen/preconcurrency_conformances_backdeploy.swift b/test/SILGen/preconcurrency_conformances_backdeploy.swift
index 6462f12a70d..df8f021b279 100644
--- a/test/SILGen/preconcurrency_conformances_backdeploy.swift
+++ b/test/SILGen/preconcurrency_conformances_backdeploy.swift
@@ -1,4 +1,4 @@
-// RUN: %target-swift-frontend -primary-file %s -target %target-cpu-apple-macosx10.14 -enable-experimental-feature DynamicActorIsolation -emit-silgen -o - | %FileCheck %s
+// RUN: %target-swift-frontend -primary-file %s -target %target-cpu-apple-macosx10.14 -enable-upcoming-feature DynamicActorIsolation -emit-silgen -o - | %FileCheck %s
 
 // REQUIRES: asserts
 // REQUIRES: concurrency