Index: clang-tools-extra/test/clang-tidy/readability-redundant-declaration.cpp
===================================================================
--- clang-tools-extra/test/clang-tidy/readability-redundant-declaration.cpp
+++ clang-tools-extra/test/clang-tidy/readability-redundant-declaration.cpp
@@ -1,7 +1,7 @@
 // RUN: %check_clang_tidy %s readability-redundant-declaration %t -- \
 // RUN:   -config="{CheckOptions: \
 // RUN:             [{key: readability-redundant-declaration.IgnoreMacros, \
-// RUN:               value: 0}]}"
+// RUN:               value: 0}]}" -- -fno-ms-compatibility
 
 extern int Xyz;
 extern int Xyz; // Xyz