diff --git a/lib/Sema/Sema.h b/lib/Sema/Sema.h
index 5a53374..8cf2af0 100644
--- a/lib/Sema/Sema.h
+++ b/lib/Sema/Sema.h
@@ -176,11 +176,6 @@
   /// we can check for duplicates and find local method declarations.
   llvm::SmallVector<ObjCCategoryImplDecl*, 8> ObjCCategoryImpls;
   
-  /// ObjCProtocols - Keep track of all protocol declarations declared
-  /// with @protocol keyword, so that we can emit errors on duplicates and
-  /// find the declarations when needed.
-  llvm::DenseMap<IdentifierInfo*, ObjCProtocolDecl*> ObjCProtocols;
-
   /// ObjCInterfaceDecls - Keep track of all class declarations declared
   /// with @interface, so that we can emit errors on duplicates and
   /// find the declarations when needed. 
@@ -769,11 +764,13 @@
     /// namespace alias definition, ignoring non-namespace names (C++
     /// [basic.lookup.udir]p1).
     LookupNamespaceName,
-    // Look up an ordinary name that is going to be redeclared as a
-    // name with linkage. This lookup ignores any declarations that
-    // are outside of the current scope unless they have linkage. See 
-    // C99 6.2.2p4-5 and C++ [basic.link]p6.
-    LookupRedeclarationWithLinkage
+    /// Look up an ordinary name that is going to be redeclared as a
+    /// name with linkage. This lookup ignores any declarations that
+    /// are outside of the current scope unless they have linkage. See 
+    /// C99 6.2.2p4-5 and C++ [basic.link]p6.
+    LookupRedeclarationWithLinkage,
+    /// Look up the name of an Objective-C protocol.
+    LookupProtocolName
   };
 
   /// @brief Represents the results of name lookup.
@@ -1025,6 +1022,7 @@
     case Sema::LookupTagName:
     case Sema::LookupMemberName:
     case Sema::LookupRedeclarationWithLinkage: // FIXME: check linkage, scoping
+    case Sema::LookupProtocolName:
       return D->isInIdentifierNamespace(IDNS);
       
     case Sema::LookupOperatorName:
@@ -1058,6 +1056,8 @@
                                 bool AllowBuiltinCreation = true,
                                 SourceLocation Loc = SourceLocation());
 
+  ObjCProtocolDecl *LookupProtocol(IdentifierInfo *II);
+
   void LookupOverloadedOperatorName(OverloadedOperatorKind Op, Scope *S,
                                     QualType T1, QualType T2, 
                                     FunctionSet &Functions);
diff --git a/lib/Sema/SemaDeclObjC.cpp b/lib/Sema/SemaDeclObjC.cpp
index 6702eb9..7badaa3 100644
--- a/lib/Sema/SemaDeclObjC.cpp
+++ b/lib/Sema/SemaDeclObjC.cpp
@@ -222,7 +222,7 @@
   for (ObjCList<ObjCProtocolDecl>::iterator I = PList.begin(),
        E = PList.end(); I != E; ++I) {
        
-    if (ObjCProtocolDecl *PDecl = ObjCProtocols[(*I)->getIdentifier()]) {
+    if (ObjCProtocolDecl *PDecl = LookupProtocol((*I)->getIdentifier())) {
       if (PDecl->getIdentifier() == PName) {
         Diag(Ploc, diag::err_protocol_has_circular_dependency);
         Diag(PrevLoc, diag::note_previous_definition);
@@ -243,7 +243,7 @@
                                   AttributeList *AttrList) {
   // FIXME: Deal with AttrList.
   assert(ProtocolName && "Missing protocol identifier");
-  ObjCProtocolDecl *PDecl = ObjCProtocols[ProtocolName];
+  ObjCProtocolDecl *PDecl = LookupProtocol(ProtocolName);
   if (PDecl) {
     // Protocol already seen. Better be a forward protocol declaration
     if (!PDecl->isForwardDecl()) {
@@ -265,10 +265,8 @@
   } else {
     PDecl = ObjCProtocolDecl::Create(Context, CurContext, 
                                      AtProtoInterfaceLoc,ProtocolName);
-    // FIXME: PushOnScopeChains?
-    CurContext->addDecl(Context, PDecl);
+    PushOnScopeChains(PDecl, TUScope);
     PDecl->setForwardDecl(false);
-    ObjCProtocols[ProtocolName] = PDecl;
   }
   if (AttrList)
     ProcessDeclAttributeList(PDecl, AttrList);
@@ -291,7 +289,7 @@
                               unsigned NumProtocols,
                               llvm::SmallVectorImpl<DeclPtrTy> &Protocols) {
   for (unsigned i = 0; i != NumProtocols; ++i) {
-    ObjCProtocolDecl *PDecl = ObjCProtocols[ProtocolId[i].first];
+    ObjCProtocolDecl *PDecl = LookupProtocol(ProtocolId[i].first);
     if (!PDecl) {
       Diag(ProtocolId[i].second, diag::err_undeclared_protocol)
         << ProtocolId[i].first;
@@ -514,12 +512,11 @@
   
   for (unsigned i = 0; i != NumElts; ++i) {
     IdentifierInfo *Ident = IdentList[i].first;
-    ObjCProtocolDecl *&PDecl = ObjCProtocols[Ident];
+    ObjCProtocolDecl *PDecl = LookupProtocol(Ident);
     if (PDecl == 0) { // Not already seen?
       PDecl = ObjCProtocolDecl::Create(Context, CurContext, 
                                        IdentList[i].second, Ident);
-      // FIXME: PushOnScopeChains?
-      CurContext->addDecl(Context, PDecl);
+      PushOnScopeChains(PDecl, TUScope);
     }
     if (attrList)
       ProcessDeclAttributeList(PDecl, attrList);
diff --git a/lib/Sema/SemaExprObjC.cpp b/lib/Sema/SemaExprObjC.cpp
index 23f6f94..1df7f3d 100644
--- a/lib/Sema/SemaExprObjC.cpp
+++ b/lib/Sema/SemaExprObjC.cpp
@@ -128,7 +128,7 @@
                                                    SourceLocation ProtoLoc,
                                                    SourceLocation LParenLoc,
                                                    SourceLocation RParenLoc) {
-  ObjCProtocolDecl* PDecl = ObjCProtocols[ProtocolId];
+  ObjCProtocolDecl* PDecl = LookupProtocol(ProtocolId);
   if (!PDecl) {
     Diag(ProtoLoc, diag::err_undeclared_protocol) << ProtocolId;
     return true;
diff --git a/lib/Sema/SemaLookup.cpp b/lib/Sema/SemaLookup.cpp
index 0b11d9c..613c30b 100644
--- a/lib/Sema/SemaLookup.cpp
+++ b/lib/Sema/SemaLookup.cpp
@@ -293,6 +293,10 @@
   case Sema::LookupNamespaceName:
     IDNS = Decl::IDNS_Ordinary | Decl::IDNS_Tag | Decl::IDNS_Member;
     break;
+
+  case Sema::LookupProtocolName:
+    IDNS = Decl::IDNS_Protocol;
+    break;
   }
   return IDNS;
 }
@@ -831,6 +835,10 @@
         S = S->getParent();
       IDNS = Decl::IDNS_Ordinary;
       break;
+
+    case Sema::LookupProtocolName:
+      IDNS = Decl::IDNS_Protocol;
+      break;
     }
 
     // Scan up the scope chain looking for a decl that matches this
@@ -1480,6 +1488,12 @@
   return false;
 }
 
+/// \brief Find the protocol with the given name, if any.
+ObjCProtocolDecl *Sema::LookupProtocol(IdentifierInfo *II) {
+  Decl *D = LookupName(TUScope, II, LookupProtocolName).getAsDecl();
+  return cast_or_null<ObjCProtocolDecl>(D);
+}
+
 void Sema::LookupOverloadedOperatorName(OverloadedOperatorKind Op, Scope *S,
                                         QualType T1, QualType T2, 
                                         FunctionSet &Functions) {