diff --git a/lib/private-libwebsockets.h b/lib/private-libwebsockets.h
index 2b3e10a1..98cf5050 100755
--- a/lib/private-libwebsockets.h
+++ b/lib/private-libwebsockets.h
@@ -149,8 +149,10 @@
 #endif
 
 #ifndef HAVE_BZERO
+#ifndef bzero
 #define bzero(b, len) (memset((b), '\0', (len)), (void) 0)
 #endif
+#endif
 
 #ifndef HAVE_STRERROR
 #define strerror(x) ""