diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 26f8b25..9d7f13c 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -4843,6 +4843,22 @@
       ND.dropAttr<SelectAnyAttr>();
     }
   }
+
+  // dll attributes require external linkage.
+  if (const DLLImportAttr *Attr = ND.getAttr<DLLImportAttr>()) {
+    if (!ND.isExternallyVisible()) {
+      S.Diag(ND.getLocation(), diag::err_attribute_dll_not_extern)
+        << &ND << Attr;
+      ND.setInvalidDecl();
+    }
+  }
+  if (const DLLExportAttr *Attr = ND.getAttr<DLLExportAttr>()) {
+    if (!ND.isExternallyVisible()) {
+      S.Diag(ND.getLocation(), diag::err_attribute_dll_not_extern)
+        << &ND << Attr;
+      ND.setInvalidDecl();
+    }
+  }
 }
 
 static void checkDLLAttributeRedeclaration(Sema &S, NamedDecl *OldDecl,