1 files changed, 1 insertions, 1 deletions
diff --git a/error.c b/error.c
index f988f387c1..544c8c798d 100644
--- a/error.c
+++ b/error.c
@@ -506,7 +506,7 @@ static const syserr_index_entry syserr_index[]= {
 static VALUE *syserr_list;
 #endif
 
-#if !defined NT && !defined sys_nerr
+#if !defined(NT) && !defined(__FreeBSD__) && !defined(__NetBSD__) && !defined(__OpenBSD__) && !defined(sys_nerr)
 extern int sys_nerr;
 #endif