diff --git a/lib/cmdline.c b/lib/cmdline.c
index 5546bf588780..90ed997d9570 100644
--- a/lib/cmdline.c
+++ b/lib/cmdline.c
@@ -260,7 +260,7 @@ 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]) {