Index: lib/Sema/SemaDecl.cpp
===================================================================
--- lib/Sema/SemaDecl.cpp
+++ lib/Sema/SemaDecl.cpp
@@ -8673,9 +8673,12 @@
       // member function definition.
 
       // MSVC permits the use of a 'static' storage specifier on an out-of-line
-      // member function template declaration, warn about this.
+      // member function template declaration and class member template
+      // declaration (MSVC versions before 2015), warn about this.
       Diag(D.getDeclSpec().getStorageClassSpecLoc(),
-           NewFD->getDescribedFunctionTemplate() && getLangOpts().MSVCCompat
+           ((!getLangOpts().isCompatibleWithMSVC(LangOptions::MSVC2015) &&
+             cast<CXXRecordDecl>(DC)->getDescribedClassTemplate()) ||
+           (getLangOpts().MSVCCompat && NewFD->getDescribedFunctionTemplate()))
            ? diag::ext_static_out_of_line : diag::err_static_out_of_line)
         << FixItHint::CreateRemoval(D.getDeclSpec().getStorageClassSpecLoc());
     }
Index: test/SemaCXX/warn-static-outside-class-definition.cpp
===================================================================
--- test/SemaCXX/warn-static-outside-class-definition.cpp
+++ test/SemaCXX/warn-static-outside-class-definition.cpp
@@ -1,4 +1,5 @@
 // RUN: %clang_cc1 -fms-compatibility -fsyntax-only -verify %s
+// RUN: %clang_cc1 -fms-compatibility -fsyntax-only -fms-compatibility-version=18.0 -verify %s
 
 struct C {
   template <typename T> static int foo(T);
@@ -9,3 +10,10 @@
   return 0;
 }
 
+template <class T> struct S { 
+  void f();
+};
+
+template <class T> static void S<T>::f() {
+  //expected-warning@-1 {{'static' can only be specified inside the class definition}}
+}