diff --git a/lib/cmdline.c b/lib/cmdline.c
index fbb9981a04a41b0e5c5599340362aa50f1e2f5c6..75cb23b0ee69c2f3a6921f06c39878c5a41f69ce 100644
--- a/lib/cmdline.c
+++ b/lib/cmdline.c
@@ -235,7 +235,7 @@ char *next_arg(char *args, char **param, char **val)
 				args[i-1] = '\0';
 		}
 	}
-	if (quoted && args[i-1] == '"')
+	if (quoted && i > 0 && args[i-1] == '"')
 		args[i-1] = '\0';
 
 	if (args[i]) {