diff --git a/ppl/src/test/java/org/opensearch/sql/ppl/antlr/PPLSyntaxParserTest.java b/ppl/src/test/java/org/opensearch/sql/ppl/antlr/PPLSyntaxParserTest.java
index 04f7d27b61..5601bda485 100644
--- a/ppl/src/test/java/org/opensearch/sql/ppl/antlr/PPLSyntaxParserTest.java
+++ b/ppl/src/test/java/org/opensearch/sql/ppl/antlr/PPLSyntaxParserTest.java
@@ -421,7 +421,7 @@ public void testCanParseTimestampdiffFunction() {
   @Test
   public void testCanParseFillNullSameValue() {
     assertNotNull(new PPLSyntaxParser().parse("SOURCE=test | fillnull with 0 in a"));
-    assertNotNull(new PPLSyntaxParser().parse("SOURCE=test | fillnull with 0 in a,b"));
+    assertNotNull(new PPLSyntaxParser().parse("SOURCE=test | fillnull with 0 in a, b"));
   }
 
   @Test