diff --git a/libbb/xfuncs.c b/libbb/xfuncs.c
index acd4d6985..869c04a4c 100644
--- a/libbb/xfuncs.c
+++ b/libbb/xfuncs.c
@@ -86,6 +86,7 @@ FILE *xfopen(const char *path, const char *mode)
 }
 
 /* Stupid gcc always includes its own builtin strlen()... */
+#undef strlen
 size_t xstrlen(const char *string)
 {
 	    return(strlen(string));