diff --git configure.ac configure.ac
index 437db76..360a948 100644
--- configure.ac
+++ configure.ac
@@ -144,6 +144,7 @@ AS_IF([test "x$enable_dynamic_ld" = "xyes"], [
   LDFLAGS="$LDFLAGS -Wl,--dynamic-linker=/lib64/ld64.so.2"
 ])
 
+CPPFLAGS="$CPPFLAGS -Wno-implicit-fallthrough"
 CFLAGS="$CFLAGS -Werror -DMST_UL"
 CXXFLAGS="$CXXFLAGS -Werror -DMST_UL"