diff --git a/lib/IRGen/GenValueWitness.cpp b/lib/IRGen/GenValueWitness.cpp
index df5c392b31c..12e30491912 100644
--- a/lib/IRGen/GenValueWitness.cpp
+++ b/lib/IRGen/GenValueWitness.cpp
@@ -1396,9 +1396,9 @@ getAddrOfKnownValueWitnessTable(IRGenModule &IGM, CanType type,
                                 bool relativeReference) {
   // Native PE binaries shouldn't reference data symbols across DLLs, so disable
   // this on Windows, unless we're forming a relative indirectable reference.
-  if (IGM.useDllStorage() && !relativeReference)
+  if (useDllStorage(IGM.Triple) && !relativeReference)
     return {};
-  
+
   if (auto nom = type->getAnyNominal()) {
     // TODO: Non-C enums have extra inhabitants and also need additional value
     // witnesses for their tag manipulation (except when they're empty, in
diff --git a/lib/IRGen/IRGenModule.cpp b/lib/IRGen/IRGenModule.cpp
index 0ccee83c1fc..efc2d3c7425 100644
--- a/lib/IRGen/IRGenModule.cpp
+++ b/lib/IRGen/IRGenModule.cpp
@@ -1057,10 +1057,6 @@ bool isStandardLibrary(const llvm::Module &M) {
 }
 }
 
-bool IRGenModule::isStandardLibrary() const {
-  return ::isStandardLibrary(Module);
-}
-
 llvm::FunctionType *swift::getRuntimeFnType(llvm::Module &Module,
                                            llvm::ArrayRef<llvm::Type*> retTypes,
                                            llvm::ArrayRef<llvm::Type*> argTypes) {
@@ -1293,7 +1289,7 @@ IRGenModule::createStringConstant(StringRef Str, bool willBeRelativelyAddressed,
     if (NAME)                                                                  \
       return NAME;                                                             \
     NAME = Module.getOrInsertGlobal(SYM, FullExistentialTypeMetadataStructTy); \
-    if (useDllStorage() && !isStandardLibrary())                               \
+    if (!getSwiftModule()->isStdlibModule())                                   \
       ApplyIRLinkage(IRLinkage::ExternalImport)                                \
           .to(cast<llvm::GlobalVariable>(NAME));                               \
     return NAME;                                                               \
@@ -2127,8 +2123,6 @@ void IRGenModule::error(SourceLoc loc, const Twine &message) {
                          message.toStringRef(buffer));
 }
 
-bool IRGenModule::useDllStorage() { return ::useDllStorage(Triple); }
-
 // In embedded swift features are available independent of deployment and
 // runtime targets because the runtime library is always statically linked
 // to the program.
@@ -2152,9 +2146,9 @@ bool IRGenModule::shouldPrespecializeGenericMetadata() {
   auto canPrespecializeTarget =
       (Triple.isOSDarwin() || Triple.isOSWindows() ||
        (Triple.isOSLinux() && !(Triple.isARM() && Triple.isArch32Bit())));
-  if (canPrespecializeTarget && isStandardLibrary()) {
+  if (canPrespecializeTarget && getSwiftModule()->isStdlibModule())
     return IRGen.Opts.PrespecializeGenericMetadata;
-  }
+
   auto &context = getSwiftModule()->getASTContext();
   auto deploymentAvailability = AvailabilityRange::forDeploymentTarget(context);
   return IRGen.Opts.PrespecializeGenericMetadata &&
diff --git a/lib/IRGen/IRGenModule.h b/lib/IRGen/IRGenModule.h
index 38976ca8ce3..070d07cb0ff 100644
--- a/lib/IRGen/IRGenModule.h
+++ b/lib/IRGen/IRGenModule.h
@@ -968,8 +968,6 @@ public:
   void fatal_unimplemented(SourceLoc, StringRef Message);
   void error(SourceLoc loc, const Twine &message);
 
-  bool useDllStorage();
-
   bool shouldPrespecializeGenericMetadata();
   
   bool canMakeStaticObjectReadOnly(SILType objectType);
@@ -1510,7 +1508,6 @@ public:
   llvm::Module *getModule() const;
   llvm::AttributeList getAllocAttrs();
   llvm::Constant *getDeletedAsyncMethodErrorAsyncFunctionPointer();
-  bool isStandardLibrary() const;
 
 private:
   llvm::Constant *EmptyTupleMetadata = nullptr;
diff --git a/lib/IRGen/MetadataRequest.cpp b/lib/IRGen/MetadataRequest.cpp
index 9e1812b1f70..699f24fb427 100644
--- a/lib/IRGen/MetadataRequest.cpp
+++ b/lib/IRGen/MetadataRequest.cpp
@@ -602,7 +602,7 @@ irgen::tryEmitConstantHeapMetadataRef(IRGenModule &IGM,
 ConstantReference
 irgen::tryEmitConstantTypeMetadataRef(IRGenModule &IGM, CanType type,
                                       SymbolReferenceKind refKind) {
-  if (IGM.isStandardLibrary())
+  if (IGM.getSwiftModule()->isStdlibModule())
     return ConstantReference();
   if (isCanonicalCompleteTypeMetadataStaticallyAddressable(IGM, type))
     return ConstantReference();