diff --git a/lib/Sema/TypeCheckProtocol.cpp b/lib/Sema/TypeCheckProtocol.cpp
index 11ed775786a..fdb56890015 100644
--- a/lib/Sema/TypeCheckProtocol.cpp
+++ b/lib/Sema/TypeCheckProtocol.cpp
@@ -1701,7 +1701,7 @@ RequirementCheck WitnessChecker::checkWitness(ValueDecl *requirement,
       }
 
       if (auto adoptingNominal = DC->getSelfNominalTypeDecl()) {
-        if (adoptingNominal->getAttrs().isUnavailable(getASTContext()))
+        if (adoptingNominal->getSemanticUnavailableAttr())
           return true;
       }
 
diff --git a/test/ModuleInterface/actor_availability.swift b/test/ModuleInterface/actor_availability.swift
index adff0a8c6c2..f73f7cf1e8d 100644
--- a/test/ModuleInterface/actor_availability.swift
+++ b/test/ModuleInterface/actor_availability.swift
@@ -7,9 +7,6 @@
 
 // REQUIRES: VENDOR=apple
 
-// FIXME: rdar://107052715 temporarily disabled the test; fails on ios simulator
-// REQUIRES: rdar107052715
-
 // CHECK: #if compiler(>=5.3) && $Actors
 // CHECK-NEXT: public actor ActorWithImplicitAvailability {
 public actor ActorWithImplicitAvailability {
diff --git a/test/decl/protocol/req/unavailable.swift b/test/decl/protocol/req/unavailable.swift
index 9dfc401453e..1e51ef8c27a 100644
--- a/test/decl/protocol/req/unavailable.swift
+++ b/test/decl/protocol/req/unavailable.swift
@@ -64,6 +64,14 @@ extension ConformsToP5: P {
   func foo(bar: Foo) { }
 }
 
+@available(*, unavailable)
+enum UnavailableEnum {
+  struct ConformsToP6: P {
+    @available(*, unavailable)
+    func foo(bar: Foo) { }
+  }
+}
+
 // Include message string from @available attribute if provided
 protocol Unavail {
   associatedtype T