diff --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp
index e05f3fe..4b4a47d 100644
--- a/clang/lib/Sema/SemaTemplate.cpp
+++ b/clang/lib/Sema/SemaTemplate.cpp
@@ -6775,7 +6775,7 @@
       // Do not warn for class scope explicit specialization during
       // instantiation, warning was already emitted during pattern
       // semantic analysis.
-      if (!S.ActiveTemplateInstantiations.size())
+      if (!S.inTemplateInstantiation())
         S.Diag(Loc, diag::ext_function_specialization_in_class)
           << Specialized;
     } else {