diff --git a/command/leave.go b/command/leave.go
index b402f9e35d..819e10d67d 100644
--- a/command/leave.go
+++ b/command/leave.go
@@ -33,6 +33,12 @@ func (c *LeaveCommand) Run(args []string) int {
 	if err := cmdFlags.Parse(args); err != nil {
 		return 1
 	}
+	nonFlagArgs := cmdFlags.Args()
+	if len(nonFlagArgs) > 0 {
+		c.Ui.Error(fmt.Sprintf("Error found unexpected args: %v", nonFlagArgs))
+		c.Ui.Output(c.Help())
+		return 1
+	}
 
 	client, err := RPCClient(*rpcAddr)
 	if err != nil {
diff --git a/command/leave_test.go b/command/leave_test.go
index 2a5caaccd7..865df8e754 100644
--- a/command/leave_test.go
+++ b/command/leave_test.go
@@ -27,3 +27,17 @@ func TestLeaveCommandRun(t *testing.T) {
 		t.Fatalf("bad: %#v", ui.OutputWriter.String())
 	}
 }
+
+func TestLeaveCommandFailOnNonFlagArgs(t *testing.T) {
+	a1 := testAgent(t)
+	defer a1.Shutdown()
+
+	ui := new(cli.MockUi)
+	c := &LeaveCommand{Ui: ui}
+	args := []string{"-rpc-addr=" + a1.addr, "appserver1"}
+
+	code := c.Run(args)
+	if code == 0 {
+		t.Fatalf("bad: failed to check for unexpected args")
+	}
+}