diff --git a/CommandListener.cpp b/CommandListener.cpp
index 3a327f1..562b5c2 100644
--- a/CommandListener.cpp
+++ b/CommandListener.cpp
@@ -240,6 +240,10 @@ int CommandListener::StorageCmd::runCommand(SocketClient *cli,
         DIR *dir;
         struct dirent *de;
 
+        if (argc < 3) {
+            cli->sendMsg(ResponseCode::CommandSyntaxError, "Missing Argument: user <mountpoint>", false);
+            return 0;
+        }
         if (!(dir = opendir("/proc"))) {
             cli->sendMsg(ResponseCode::OperationFailed, "Failed to open /proc", true);
             return 0;