diff --git a/m4/ax_harden_compiler_flags.m4 b/m4/ax_harden_compiler_flags.m4
index d4377a70e..f33e00748 100644
--- a/m4/ax_harden_compiler_flags.m4
+++ b/m4/ax_harden_compiler_flags.m4
@@ -145,7 +145,9 @@
       AX_APPEND_COMPILE_FLAGS([-Wpointer-arith],,[$ax_append_compile_cflags_extra])
       AX_APPEND_COMPILE_FLAGS([-Wpointer-sign],,[$ax_append_compile_cflags_extra])
 dnl      AX_APPEND_COMPILE_FLAGS([-Wredundant-decls],,[$ax_append_compile_cflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wshadow],,[$ax_append_compile_cflags_extra])
+      AS_CASE([$CFLAGS], [*-Wno-shadow*], [], [
+        AX_APPEND_COMPILE_FLAGS([-Wshadow],,[$ax_append_compile_cflags_extra])
+        ])
       AX_APPEND_COMPILE_FLAGS([-Wshorten-64-to-32],,[$ax_append_compile_cflags_extra])
       AX_APPEND_COMPILE_FLAGS([-Wsign-compare],,[$ax_append_compile_cflags_extra])
       AX_APPEND_COMPILE_FLAGS([-Wstrict-overflow=1],,[$ax_append_compile_cflags_extra])
@@ -207,7 +209,9 @@ dnl      AX_APPEND_COMPILE_FLAGS([-Wredundant-decls],,[$ax_append_compile_cflags
       AX_APPEND_COMPILE_FLAGS([-Woverloaded-virtual],,[$ax_append_compile_cxxflags_extra])
       AX_APPEND_COMPILE_FLAGS([-Wpointer-arith],,[$ax_append_compile_cxxflags_extra])
 dnl      AX_APPEND_COMPILE_FLAGS([-Wredundant-decls],,[$ax_append_compile_cxxflags_extra])
-      AX_APPEND_COMPILE_FLAGS([-Wshadow],,[$ax_append_compile_cxxflags_extra])
+      AS_CASE([$CFLAGS], [*-Wno-shadow*], [], [
+        AX_APPEND_COMPILE_FLAGS([-Wshadow],,[$ax_append_compile_cxxflags_extra])
+        ])
       AX_APPEND_COMPILE_FLAGS([-Wshorten-64-to-32],,[$ax_append_compile_cxxflags_extra])
       AX_APPEND_COMPILE_FLAGS([-Wsign-compare],,[$ax_append_compile_cxxflags_extra])
       AX_APPEND_COMPILE_FLAGS([-Wstrict-overflow=1],,[$ax_append_compile_cxxflags_extra])