diff --git a/configure.ac b/configure.ac
index 24c53ca0c..33fdfcbed 100644
--- a/configure.ac
+++ b/configure.ac
@@ -684,7 +684,7 @@ AC_PROG_SED
 LXC_CHECK_TLS
 
 AX_CHECK_COMPILE_FLAG([-fdiagnostics-color], [CFLAGS="$CFLAGS -fdiagnostics-color"],,[-Werror])
-AX_CHECK_COMPILE_FLAG([-fdiagnostics-color], [CFLAGS="$CFLAGS -Wimplicit-fallthrough"],,[-Werror])
+AX_CHECK_COMPILE_FLAG([-implicit-fallthrough], [CFLAGS="$CFLAGS -Wimplicit-fallthrough"],,[-Werror])
 
 CFLAGS="$CFLAGS -Wvla -std=gnu11"
 if test "x$enable_werror" = "xyes"; then