diff --git a/maven-projects/spark/graphar/src/main/scala/org/apache/graphar/example/LdbcSample2GraphAr.scala b/maven-projects/spark/graphar/src/main/scala/org/apache/graphar/example/LdbcSample2GraphAr.scala
index 314cb397c..fe4a16b9b 100644
--- a/maven-projects/spark/graphar/src/main/scala/org/apache/graphar/example/LdbcSample2GraphAr.scala
+++ b/maven-projects/spark/graphar/src/main/scala/org/apache/graphar/example/LdbcSample2GraphAr.scala
@@ -92,7 +92,8 @@ object LdbcSample2GraphAr {
     writer.PutVertexData("Person", person_df)
 
     // read edges with type "Person"->"Knows"->"Person" from given path as a DataFrame
-    // FIXME(@acezen): the schema should be inferred from the data
+    // FIXME(@acezen): the schema should be inferred from the data, but graphar spark
+    // library does not support timestamp type yet
     val schema = StructType(
       Array(
         StructField("src", IntegerType, true),