diff --git a/src/platform_bsdlike.c b/src/platform_bsdlike.c
index 2ccf874..ffe1e64 100644
--- a/src/platform_bsdlike.c
+++ b/src/platform_bsdlike.c
@@ -1,4 +1,8 @@
+#ifdef __OpenBSD__
+#define _BSD_SOURCE // to obtain asprintf/vasprintf
+#else
 #define _GNU_SOURCE // to obtain asprintf/vasprintf
+#endif
 #include "platform.h"
 
 #include <stdio.h>