diff --git a/include/swift/Serialization/ModuleFile.h b/include/swift/Serialization/ModuleFile.h
index 256a01f6eac..5928c2a281c 100644
--- a/include/swift/Serialization/ModuleFile.h
+++ b/include/swift/Serialization/ModuleFile.h
@@ -620,6 +620,13 @@ public:
     return static_cast<Status>(Bits.Status);
   }
 
+  /// Transfers ownership of a buffer that might contain source code where
+  /// other parts of the compiler could have emitted diagnostics, to keep them
+  /// alive even if the ModuleFile is destroyed.
+  ///
+  /// Should only be called when getStatus() indicates a failure.
+  std::unique_ptr<llvm::MemoryBuffer> takeBufferForDiagnostics();
+
   /// Returns the list of modules this module depends on.
   ArrayRef<Dependency> getDependencies() const {
     return Dependencies;
diff --git a/include/swift/Serialization/SerializedModuleLoader.h b/include/swift/Serialization/SerializedModuleLoader.h
index 13db71116b1..00fa1d52a31 100644
--- a/include/swift/Serialization/SerializedModuleLoader.h
+++ b/include/swift/Serialization/SerializedModuleLoader.h
@@ -29,6 +29,8 @@ private:
   using LoadedModulePair = std::pair<std::unique_ptr<ModuleFile>, unsigned>;
   std::vector<LoadedModulePair> LoadedModuleFiles;
 
+  SmallVector<std::unique_ptr<llvm::MemoryBuffer>, 2> OrphanedMemoryBuffers;
+
   explicit SerializedModuleLoader(ASTContext &ctx, DependencyTracker *tracker);
 
 public:
diff --git a/lib/Serialization/ModuleFile.cpp b/lib/Serialization/ModuleFile.cpp
index 68576db2017..dc237301300 100644
--- a/lib/Serialization/ModuleFile.cpp
+++ b/lib/Serialization/ModuleFile.cpp
@@ -1457,6 +1457,17 @@ Status ModuleFile::associateWithFileContext(FileUnit *file,
   return getStatus();
 }
 
+std::unique_ptr<llvm::MemoryBuffer> ModuleFile::takeBufferForDiagnostics() {
+  assert(getStatus() != Status::Valid);
+
+  // Today, the only buffer that might have diagnostics in them is the input
+  // buffer, and even then only if it has imported module contents.
+  if (!importedHeaderInfo.contents.empty())
+    return std::move(ModuleInputBuffer);
+
+  return nullptr;
+}
+
 ModuleFile::~ModuleFile() { }
 
 void ModuleFile::lookupValue(DeclName name,
diff --git a/lib/Serialization/SerializedModuleLoader.cpp b/lib/Serialization/SerializedModuleLoader.cpp
index d7f8729b454..02edb2e7b45 100644
--- a/lib/Serialization/SerializedModuleLoader.cpp
+++ b/lib/Serialization/SerializedModuleLoader.cpp
@@ -223,7 +223,14 @@ FileUnit *SerializedModuleLoader::loadAST(
     M.removeFile(*fileUnit);
   }
 
-  // This is the failure path. If we have a location, diagnose the issue.
+  // From here on is the failure path.
+
+  // Even though the module failed to load, it's possible its contents include
+  // a source buffer that need to survive because it's already been used for
+  // diagnostics.
+  if (auto orphanedBuffer = loadedModuleFile->takeBufferForDiagnostics())
+    OrphanedMemoryBuffers.push_back(std::move(orphanedBuffer));
+
   if (!diagLoc)
     return nullptr;