diff --git a/lib/Parse/ParseDeclCXX.cpp b/lib/Parse/ParseDeclCXX.cpp
index d852127..238048f 100644
--- a/lib/Parse/ParseDeclCXX.cpp
+++ b/lib/Parse/ParseDeclCXX.cpp
@@ -132,7 +132,7 @@
   
   CXXScopeSpec SS;
   // Parse (optional) nested-name-specifier.
-  ParseOptionalCXXScopeSpecifier(SS, /*ObjectType=*/0, false);
+  ParseOptionalCXXScopeSpecifier(SS, /*ObjectType=*/0, false, false);
 
   if (SS.isInvalid() || Tok.isNot(tok::identifier)) {
     Diag(Tok, diag::err_expected_namespace_name);
@@ -260,7 +260,7 @@
   
   CXXScopeSpec SS;
   // Parse (optional) nested-name-specifier.
-  ParseOptionalCXXScopeSpecifier(SS, /*ObjectType=*/0, false);
+  ParseOptionalCXXScopeSpecifier(SS, /*ObjectType=*/0, false, false);
 
   IdentifierInfo *NamespcName = 0;
   SourceLocation IdentLoc = SourceLocation();
@@ -322,7 +322,7 @@
     IsTypeName = false;
 
   // Parse nested-name-specifier.
-  ParseOptionalCXXScopeSpecifier(SS, /*ObjectType=*/0, false);
+  ParseOptionalCXXScopeSpecifier(SS, /*ObjectType=*/0, false, false);
 
   AttributeList *AttrList = 0;
 
@@ -601,7 +601,7 @@
   // Parse the (optional) nested-name-specifier.
   CXXScopeSpec SS;
   if (getLang().CPlusPlus &&
-      ParseOptionalCXXScopeSpecifier(SS, /*ObjectType=*/0, true))
+      ParseOptionalCXXScopeSpecifier(SS, /*ObjectType=*/0, true, true))
     if (Tok.isNot(tok::identifier) && Tok.isNot(tok::annot_template_id))
       Diag(Tok, diag::err_expected_ident);
 
diff --git a/lib/Parse/ParseExprCXX.cpp b/lib/Parse/ParseExprCXX.cpp
index 4eb6cd5..ae2a47b 100644
--- a/lib/Parse/ParseExprCXX.cpp
+++ b/lib/Parse/ParseExprCXX.cpp
@@ -45,10 +45,14 @@
 /// \param EnteringContext whether we will be entering into the context of
 /// the nested-name-specifier after parsing it.
 ///
+/// \param ColonIsSacred - If this is true, then a colon is valid after the
+/// specifier, so we should not try to recover from colons aggressively.
+///
 /// \returns true if a scope specifier was parsed.
 bool Parser::ParseOptionalCXXScopeSpecifier(CXXScopeSpec &SS,
                                             Action::TypeTy *ObjectType,
-                                            bool EnteringContext) {
+                                            bool EnteringContext,
+                                            bool ColonIsSacred) {
   assert(getLang().CPlusPlus &&
          "Call sites of this function should be guarded by checking for C++");
 
@@ -214,11 +218,29 @@
     //   namespace-name '::'
     //   nested-name-specifier identifier '::'
     Token Next = NextToken();
+    
+    // If we get foo:bar, this is almost certainly a typo for foo::bar.  Recover
+    // and emit a fixit hint for it.
+    if (Next.is(tok::colon) && !ColonIsSacred &&
+        Actions.IsInvalidUnlessNestedName(CurScope, SS, II, ObjectType,
+                                          EnteringContext) &&
+        // If the token after the colon isn't an identifier, it's still an
+        // error, but they probably meant something else strange so don't
+        // recover like this.
+        PP.LookAhead(1).is(tok::identifier)) {
+      Diag(Next, diag::err_unexected_colon_in_nested_name_spec)
+        << CodeModificationHint::CreateReplacement(Next.getLocation(), "::");
+      
+      // Recover as if the user wrote '::'.
+      Next.setKind(tok::coloncolon);
+    }
+    
     if (Next.is(tok::coloncolon)) {
       // We have an identifier followed by a '::'. Lookup this name
       // as the name in a nested-name-specifier.
       SourceLocation IdLoc = ConsumeToken();
-      assert(Tok.is(tok::coloncolon) && "NextToken() not working properly!");
+      assert((Tok.is(tok::coloncolon) || Tok.is(tok::colon)) &&
+             "NextToken() not working properly!");
       SourceLocation CCLoc = ConsumeToken();
 
       if (!HasScopeSpecifier) {