diff --git a/lib/libftpio/ftpio.c b/lib/libftpio/ftpio.c
index 155f954c79c6..ceb428c1ac9d 100644
--- a/lib/libftpio/ftpio.c
+++ b/lib/libftpio/ftpio.c
@@ -500,7 +500,7 @@ check_passive(FILE *fp)
 {
     char *cp = getenv("FTP_PASSIVE_MODE");
 
-    ftpPassive(fp, (cp && !strncmp(cp, "YES", 3)));
+    ftpPassive(fp, (cp && strncasecmp(cp, "no", 2)));
 }
 
 static void