Index: lib/Sema/SemaOpenMP.cpp
===================================================================
--- lib/Sema/SemaOpenMP.cpp
+++ lib/Sema/SemaOpenMP.cpp
@@ -12433,6 +12433,11 @@
   LookupResult Lookup(*this, Id, LookupOrdinaryName);
   LookupParsedName(Lookup, CurScope, &ScopeSpec, true);
 
+  if (Lookup.empty()) {
+    Diag(Id.getLoc(), diag::err_undeclared_var_use) << Id.getName();
+    return;
+  }
+
   if (Lookup.isAmbiguous())
     return;
   Lookup.suppressDiagnostics();
Index: test/OpenMP/declare_target_messages.cpp
===================================================================
--- test/OpenMP/declare_target_messages.cpp
+++ test/OpenMP/declare_target_messages.cpp
@@ -13,6 +13,10 @@
 
 #pragma omp declare target map(a) // expected-error {{unexpected 'map' clause, only 'to' or 'link' clauses expected}}
 
+#pragma omp declare target to(i) // expected-error {{use of undeclared identifier 'i'}}
+
+#pragma omp declare target link(j) // expected-error {{use of undeclared identifier 'j'}}
+
 void c(); // expected-warning {{declaration is not declared in any declare target region}}
 
 extern int b;