diff --git a/clang/include/clang/AST/DeclObjC.h b/clang/include/clang/AST/DeclObjC.h
index 789b75558de1..f475350e8fba 100644
--- a/clang/include/clang/AST/DeclObjC.h
+++ b/clang/include/clang/AST/DeclObjC.h
@@ -1137,6 +1137,14 @@ public:
   SourceLocation getLocEnd() const { return EndLoc; }
   void setLocEnd(SourceLocation LE) { EndLoc = LE; }
 
+  /// Retrieves the canonical declaration of this Objective-C protocol.
+  ObjCProtocolDecl *getCanonicalDecl() {
+    return this;
+  }
+  const ObjCProtocolDecl *getCanonicalDecl() const {
+    return this;
+  }
+
   static bool classof(const Decl *D) { return classofKind(D->getKind()); }
   static bool classof(const ObjCProtocolDecl *D) { return true; }
   static bool classofKind(Kind K) { return K == ObjCProtocol; }
diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index 9784191ad80f..a990989b20f2 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -1195,10 +1195,10 @@ void ASTContext::CollectInheritedProtocols(const Decl *CDecl,
     for (ObjCInterfaceDecl::all_protocol_iterator P = OI->all_referenced_protocol_begin(),
          PE = OI->all_referenced_protocol_end(); P != PE; ++P) {
       ObjCProtocolDecl *Proto = (*P);
-      Protocols.insert(Proto);
+      Protocols.insert(Proto->getCanonicalDecl());
       for (ObjCProtocolDecl::protocol_iterator P = Proto->protocol_begin(),
            PE = Proto->protocol_end(); P != PE; ++P) {
-        Protocols.insert(*P);
+        Protocols.insert((*P)->getCanonicalDecl());
         CollectInheritedProtocols(*P, Protocols);
       }
     }
@@ -1216,7 +1216,7 @@ void ASTContext::CollectInheritedProtocols(const Decl *CDecl,
     for (ObjCCategoryDecl::protocol_iterator P = OC->protocol_begin(),
          PE = OC->protocol_end(); P != PE; ++P) {
       ObjCProtocolDecl *Proto = (*P);
-      Protocols.insert(Proto);
+      Protocols.insert(Proto->getCanonicalDecl());
       for (ObjCProtocolDecl::protocol_iterator P = Proto->protocol_begin(),
            PE = Proto->protocol_end(); P != PE; ++P)
         CollectInheritedProtocols(*P, Protocols);
@@ -1225,7 +1225,7 @@ void ASTContext::CollectInheritedProtocols(const Decl *CDecl,
     for (ObjCProtocolDecl::protocol_iterator P = OP->protocol_begin(),
          PE = OP->protocol_end(); P != PE; ++P) {
       ObjCProtocolDecl *Proto = (*P);
-      Protocols.insert(Proto);
+      Protocols.insert(Proto->getCanonicalDecl());
       for (ObjCProtocolDecl::protocol_iterator P = Proto->protocol_begin(),
            PE = Proto->protocol_end(); P != PE; ++P)
         CollectInheritedProtocols(*P, Protocols);
@@ -5178,7 +5178,7 @@ bool ASTContext::areCompatibleVectorTypes(QualType FirstVec,
 bool
 ASTContext::ProtocolCompatibleWithProtocol(ObjCProtocolDecl *lProto,
                                            ObjCProtocolDecl *rProto) const {
-  if (lProto == rProto)
+  if (declaresSameEntity(lProto, rProto))
     return true;
   for (ObjCProtocolDecl::protocol_iterator PI = rProto->protocol_begin(),
        E = rProto->protocol_end(); PI != E; ++PI)
diff --git a/clang/lib/Rewrite/RewriteObjC.cpp b/clang/lib/Rewrite/RewriteObjC.cpp
index 4b41e5a44503..1b39061d50b7 100644
--- a/clang/lib/Rewrite/RewriteObjC.cpp
+++ b/clang/lib/Rewrite/RewriteObjC.cpp
@@ -3085,7 +3085,7 @@ Stmt *RewriteObjC::RewriteObjCProtocolExpr(ObjCProtocolExpr *Exp) {
                                                 CK_BitCast,
                                                 DerefExpr);
   ReplaceStmt(Exp, castExpr);
-  ProtocolExprDecls.insert(Exp->getProtocol());
+  ProtocolExprDecls.insert(Exp->getProtocol()->getCanonicalDecl());
   // delete Exp; leak for now, see RewritePropertyOrImplicitSetter() usage for more info.
   return castExpr;
 
@@ -5185,7 +5185,7 @@ void RewriteObjCFragileABI::RewriteObjCProtocolMetaData(
     objc_protocol_methods = true;
   }
   // Do not synthesize the protocol more than once.
-  if (ObjCSynthesizedProtocols.count(PDecl))
+  if (ObjCSynthesizedProtocols.count(PDecl->getCanonicalDecl()))
     return;
   
   if (PDecl->instmeth_begin() != PDecl->instmeth_end()) {
@@ -5307,7 +5307,7 @@ void RewriteObjCFragileABI::RewriteObjCProtocolMetaData(
   Result += "};\n";
   
   // Mark this protocol as having been generated.
-  if (!ObjCSynthesizedProtocols.insert(PDecl))
+  if (!ObjCSynthesizedProtocols.insert(PDecl->getCanonicalDecl()))
     llvm_unreachable("protocol already synthesized");
   
 }