diff --git a/xmalloc.c b/xmalloc.c
index dea9dd9fe..b58323677 100644
--- a/xmalloc.c
+++ b/xmalloc.c
@@ -29,9 +29,11 @@
 void
 ssh_malloc_init(void)
 {
+#if defined(__OpenBSD__)
 	extern char *malloc_options;
 
 	malloc_options = "S";
+#endif /* __OpenBSD__ */
 }
 
 void *