diff --git a/clang/lib/Frontend/ASTUnit.cpp b/clang/lib/Frontend/ASTUnit.cpp
index e2641ccec4a7..610c20d9fb14 100644
--- a/clang/lib/Frontend/ASTUnit.cpp
+++ b/clang/lib/Frontend/ASTUnit.cpp
@@ -877,6 +877,18 @@ void AddTopLevelDeclarationToHash(Decl *D, unsigned &Hash) {
     return;
 
   if (NamedDecl *ND = dyn_cast<NamedDecl>(D)) {
+    if (EnumDecl *EnumD = dyn_cast<EnumDecl>(D)) {
+      // For an unscoped enum include the enumerators in the hash since they
+      // enter the top-level namespace.
+      if (!EnumD->isScoped()) {
+        for (EnumDecl::enumerator_iterator EI = EnumD->enumerator_begin(),
+               EE = EnumD->enumerator_end(); EI != EE; ++EI) {
+          if ((*EI)->getIdentifier())
+            Hash = llvm::HashString((*EI)->getIdentifier()->getName(), Hash);
+        }
+      }
+    }
+
     if (ND->getIdentifier())
       Hash = llvm::HashString(ND->getIdentifier()->getName(), Hash);
     else if (DeclarationName Name = ND->getDeclName()) {