diff --git a/clang/include/clang/Basic/DiagnosticParseKinds.td b/clang/include/clang/Basic/DiagnosticParseKinds.td
index 62470582870cadd9ca0554c95a3b11d3bd1f6549..32e9a08370143ea8daae0fc2fa91e87217a39de5 100644
--- a/clang/include/clang/Basic/DiagnosticParseKinds.td
+++ b/clang/include/clang/Basic/DiagnosticParseKinds.td
@@ -469,6 +469,11 @@ def err_missing_dependent_template_keyword : Error<
 def warn_missing_dependent_template_keyword : ExtWarn<
   "use 'template' keyword to treat '%0' as a dependent template name">;
 
+def ext_extern_template : Extension<
+  "extern templates are a C++11 extension">, InGroup<CXX11>;
+def warn_cxx98_compat_extern_template : Warning<
+  "extern templates are incompatible with C++98">,
+  InGroup<CXX98CompatPedantic>, DefaultIgnore;
 def warn_static_inline_explicit_inst_ignored : Warning<
   "ignoring '%select{static|inline}0' keyword on explicit template "
   "instantiation">;
diff --git a/clang/lib/Parse/Parser.cpp b/clang/lib/Parse/Parser.cpp
index 2a1e2a2de899f27021f9c3e456768820124a4075..2e0c46dbdbfea63e9109756d5a0b102012f59f34 100644
--- a/clang/lib/Parse/Parser.cpp
+++ b/clang/lib/Parse/Parser.cpp
@@ -642,6 +642,9 @@ Parser::ParseExternalDeclaration(ParsedAttributesWithRange &attrs,
       // Extern templates
       SourceLocation ExternLoc = ConsumeToken();
       SourceLocation TemplateLoc = ConsumeToken();
+      Diag(ExternLoc, getLang().CPlusPlus0x ?
+             diag::warn_cxx98_compat_extern_template :
+             diag::ext_extern_template) << SourceRange(ExternLoc, TemplateLoc);
       SourceLocation DeclEnd;
       return Actions.ConvertDeclToDeclGroup(
                   ParseExplicitInstantiation(ExternLoc, TemplateLoc, DeclEnd));
diff --git a/clang/test/CXX/temp/temp.spec/temp.explicit/p4.cpp b/clang/test/CXX/temp/temp.spec/temp.explicit/p4.cpp
index d3043741151382e3fa99dab5f47e75cc49463448..09c428e01df3b7d81af0abc5eefb4dcc0dd7dc23 100644
--- a/clang/test/CXX/temp/temp.spec/temp.explicit/p4.cpp
+++ b/clang/test/CXX/temp/temp.spec/temp.explicit/p4.cpp
@@ -43,6 +43,6 @@ namespace test0 {
     // inappropriately instantiating this template.
     void *ptr = x;
   }
-  extern template class foo<char>;
+  extern template class foo<char>; // expected-warning {{extern templates are a C++11 extension}}
   template class foo<char>;
 }
diff --git a/clang/test/SemaCXX/cxx98-compat-pedantic.cpp b/clang/test/SemaCXX/cxx98-compat-pedantic.cpp
index 28fc23a0a763ae01d1867feee96d008bfff7c23c..00532d5ac0731b56e377cdd78bcd8f2ff7c4135e 100644
--- a/clang/test/SemaCXX/cxx98-compat-pedantic.cpp
+++ b/clang/test/SemaCXX/cxx98-compat-pedantic.cpp
@@ -29,3 +29,6 @@ struct ConvertToInt {
   operator int();
 };
 int *ArraySizeConversion = new int[ConvertToInt()]; // expected-warning {{implicit conversion from array size expression of type 'ConvertToInt' to integral type 'int' is incompatible with C++98}}
+
+template<typename T> class ExternTemplate {};
+extern template class ExternTemplate<int>; // expected-warning {{extern templates are incompatible with C++98}}