diff --git a/src/known_hosts.c b/src/known_hosts.c
index 2d281e72..a9ae38c1 100644
--- a/src/known_hosts.c
+++ b/src/known_hosts.c
@@ -133,7 +133,7 @@ static char **ssh_get_knownhost_line(ssh_session session, FILE **file,
       *ptr = '\0';
     }
 
-    if (!buffer[0] || buffer[0] == '#') {
+    if (buffer[0] == '\0' || buffer[0] == '#') {
       continue; /* skip empty lines */
     }