diff --git a/internal/commands/keys.go b/internal/commands/keys.go
index be9ab578..3b1a5eef 100644
--- a/internal/commands/keys.go
+++ b/internal/commands/keys.go
@@ -16,7 +16,9 @@ func CalcKeys(argv []string) (cmaName string, group string, keys []string, keysI
 	group = "unknown"
 	cmaName = strings.ToUpper(argv[0])
 	if _, ok := containers[cmaName]; ok {
-		cmaName = fmt.Sprintf("%s-%s", cmaName, strings.ToUpper(argv[1]))
+		if len(argv) > 1 {
+			cmaName = fmt.Sprintf("%s-%s", cmaName, strings.ToUpper(argv[1]))
+		}
 	}
 	cmd, ok := redisCommands[cmaName]
 	if !ok {
diff --git a/internal/commands/keys_test.go b/internal/commands/keys_test.go
index e6c7bd74..9b9de6f9 100644
--- a/internal/commands/keys_test.go
+++ b/internal/commands/keys_test.go
@@ -40,6 +40,12 @@ func TestCalcKeys(t *testing.T) {
 	if cmd != "ZUNIONSTORE" || group != "SORTED_SET" || !testEq(keys, []string{"key", "key1", "key2"}) {
 		t.Errorf("CalcKeys(ZUNIONSTORE key 2 key1 key2) failed. cmd=%s, group=%s, keys=%v", cmd, group, keys)
 	}
+
+	// COMMAND
+	cmd, group, keys, _ = CalcKeys([]string{"COMMAND"})
+	if cmd != "COMMAND" || group != "SERVER" || !testEq(keys, []string{}) {
+		t.Errorf("CalcKeys(COMMAND) failed. cmd=%s, group=%s, keys=%v", cmd, group, keys)
+	}
 }
 
 func TestKeyHash(t *testing.T) {