diff --git a/executor.go b/executor.go
index 2de696f6a..2602f1a87 100644
--- a/executor.go
+++ b/executor.go
@@ -2005,7 +2005,12 @@ func (e *executor) executeSetRow(ctx context.Context, index string, c *pql.Call,
 	}
 
 	result, err := e.mapReduce(ctx, index, shards, c, opt, mapFn, reduceFn)
-	return result.(bool), err
+	r, ok := result.(bool)
+	if !ok {
+		err = errors.Wrapf(err, "mapReduce result is not bool,err:%s", err.Error())
+		return false, err
+	}
+	return r, err
 }
 
 // executeSetRowShard executes a SetRow() call for a single shard.