Index: include/clang/Basic/DiagnosticSemaKinds.td
===================================================================
--- include/clang/Basic/DiagnosticSemaKinds.td
+++ include/clang/Basic/DiagnosticSemaKinds.td
@@ -8808,6 +8808,9 @@
   "vector component name '%0' is an OpenCL version 2.2 feature">,
   InGroup<OpenCLUnsupportedRGBA>;
 
+def err_openclcxx_placement_new : Error<
+  "use of placement new requires explicit declaration">;
+
 // MIG routine annotations.
 def warn_mig_server_routine_does_not_return_kern_return_t : Warning<
   "'mig_server_routine' attribute only applies to routines that return a kern_return_t">,
Index: lib/Sema/SemaExprCXX.cpp
===================================================================
--- lib/Sema/SemaExprCXX.cpp
+++ lib/Sema/SemaExprCXX.cpp
@@ -2413,7 +2413,11 @@
     }
 
     if (getLangOpts().OpenCLCPlusPlus && R.empty()) {
-      Diag(StartLoc, diag::err_openclcxx_not_supported) << "default new";
+      if (PlaceArgs.empty()) {
+        Diag(StartLoc, diag::err_openclcxx_not_supported) << "default new";
+      } else {
+        Diag(StartLoc, diag::err_openclcxx_placement_new);
+      }
       return true;
     }
 
Index: test/SemaOpenCLCXX/newdelete.cl
===================================================================
--- test/SemaOpenCLCXX/newdelete.cl
+++ test/SemaOpenCLCXX/newdelete.cl
@@ -21,7 +21,7 @@
 void test_default_new_delete(void *buffer, A **pa) {
   A *a = new A;         // expected-error {{'default new' is not supported in OpenCL C++}}
   delete a;             // expected-error {{'default delete' is not supported in OpenCL C++}}
-  *pa = new (buffer) A; // expected-error {{'default new' is not supported in OpenCL C++}}
+  *pa = new (buffer) A; // expected-error {{use of placement new requires explicit declaration}}
 }
 
 // expected-note@+1 {{candidate function not viable: requires 2 arguments, but 1 was provided}}