diff --git a/shell/hostname-helper.c b/shell/hostname-helper.c
index b09d93f31..df596975e 100644
--- a/shell/hostname-helper.c
+++ b/shell/hostname-helper.c
@@ -208,6 +208,9 @@ pretty_hostname_to_ssid (const char *pretty)
 			break;
 		}
 
+		if (*p == '\0')
+			break;
+
 		prev = p;
 	}