diff --git a/socks.h b/socks.h
index a481a98..82bfa2f 100644
--- a/socks.h
+++ b/socks.h
@@ -79,7 +79,9 @@ inline void sock_close(SOCKET s)
 inline const char* sock_strerror(char* buf, size_t len)
 {
 	buf[0] = '\0';
-#if defined(__APPLE__) || defined(__FreeBSD__)
+
+#if defined(__APPLE__) || defined(__FreeBSD__) || !defined(_GNU_SOURCE) || !defined(__GLIBC__)
+
 	strerror_r(errno, buf, len);
 	return buf;
 #else