diff --git a/include/clang/Basic/DiagnosticSemaKinds.td b/include/clang/Basic/DiagnosticSemaKinds.td
index 368bdc3..15f667f 100644
--- a/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/include/clang/Basic/DiagnosticSemaKinds.td
@@ -103,7 +103,7 @@
 def ext_anon_param_requires_type_specifier : Extension<
   "type specifier required for unnamed parameter, defaults to int">;
 def err_bad_variable_name : Error<
-  "'%0' cannot be the name of a variable or data member">;
+  "%0 cannot be the name of a variable or data member">;
 def err_bad_parameter_name : Error<
   "'%0' cannot be the name of a parameter">;
 def err_parameter_name_omitted : Error<"parameter name omitted">;
diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index 1a80999..451751f 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -3720,7 +3720,7 @@
   IdentifierInfo *II = Name.getAsIdentifierInfo();
   if (!II) {
     Diag(D.getIdentifierLoc(), diag::err_bad_variable_name)
-      << Name.getAsString();
+      << Name;
     return 0;
   }
 
diff --git a/lib/Sema/SemaDeclCXX.cpp b/lib/Sema/SemaDeclCXX.cpp
index cd57dcf..031afa0 100644
--- a/lib/Sema/SemaDeclCXX.cpp
+++ b/lib/Sema/SemaDeclCXX.cpp
@@ -1487,8 +1487,14 @@
   Decl *Member;
   if (isInstField) {
     CXXScopeSpec &SS = D.getCXXScopeSpec();
+
+    // Data members must have identifiers for names.
+    if (Name.getNameKind() != DeclarationName::Identifier) {
+      Diag(Loc, diag::err_bad_variable_name)
+        << Name;
+      return 0;
+    }
     
-    // FIXME: Check that the name is an identifier!
     IdentifierInfo *II = Name.getAsIdentifierInfo();
 
     // Member field could not be with "template" keyword.
diff --git a/test/CXX/dcl.dcl/dcl.spec/dcl.type/p3-0x.cpp b/test/CXX/dcl.dcl/dcl.spec/dcl.type/p3-0x.cpp
index 9a2e4ab..9f88c03 100644
--- a/test/CXX/dcl.dcl/dcl.spec/dcl.type/p3-0x.cpp
+++ b/test/CXX/dcl.dcl/dcl.spec/dcl.type/p3-0x.cpp
@@ -7,8 +7,9 @@
 
 class K {
   virtual ~K();
-  // FIXME: the diagnostic here is really bad
-  operator struct S {} (); // expected-error 2{{}} expected-note {{}}
+  // FIXME: Diagnostic could use some work
+  operator struct S {} (); // expected-error{{ 'operator S' cannot be the name of a variable or data member}} \
+  // expected-error{{expected ';' at end of declaration list}}
 };
 
 void f() {
diff --git a/test/SemaCXX/overloaded-operator-decl.cpp b/test/SemaCXX/overloaded-operator-decl.cpp
index 5f8655c..4519a2d 100644
--- a/test/SemaCXX/overloaded-operator-decl.cpp
+++ b/test/SemaCXX/overloaded-operator-decl.cpp
@@ -43,3 +43,8 @@
     void operator()();
   } plus;
 }
+
+struct PR10839 {
+  operator int; // expected-error{{'operator int' cannot be the name of a variable or data member}}
+  int operator+; // expected-error{{'operator+' cannot be the name of a variable or data member}}
+};