diff --git a/sql/core/src/main/scala/org/apache/spark/sql/execution/joins/SortMergeJoinExec.scala b/sql/core/src/main/scala/org/apache/spark/sql/execution/joins/SortMergeJoinExec.scala
index db6626bd18abc..41c2be827ca72 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/execution/joins/SortMergeJoinExec.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/execution/joins/SortMergeJoinExec.scala
@@ -414,10 +414,12 @@ case class SortMergeJoinExec(
   }
 
   /**
-   * Generate a function to scan both sides to find a match, returns the term for
-   * matched one row from streamed side and buffered rows from buffered side.
+   * Generate a function to scan both sides to find a match, returns:
+   * 1. the function name
+   * 2. the term for matched one row from streamed side
+   * 3. the term for buffered rows from buffered side
    */
-  private def genScanner(ctx: CodegenContext): (String, String) = {
+  private def genScanner(ctx: CodegenContext): (String, String, String) = {
     // Create class member for next row from both sides.
     // Inline mutable state since not many join operations in a task
     val streamedRow = ctx.addMutableState("InternalRow", "streamedRow", forceInline = true)
@@ -518,9 +520,10 @@ case class SortMergeJoinExec(
     //            1. Inner and Left Semi join: skip the row.
     //            2. Left/Right Outer join: keep the row and return false (with `matches` being
     //                                      empty).
-    ctx.addNewFunction("findNextJoinRows",
+    val findNextJoinRowsFuncName = ctx.freshName("findNextJoinRows")
+    ctx.addNewFunction(findNextJoinRowsFuncName,
       s"""
-         |private boolean findNextJoinRows(
+         |private boolean $findNextJoinRowsFuncName(
          |    scala.collection.Iterator streamedIter,
          |    scala.collection.Iterator bufferedIter) {
          |  $streamedRow = null;
@@ -574,7 +577,7 @@ case class SortMergeJoinExec(
          |}
        """.stripMargin, inlineToOuterClass = true)
 
-    (streamedRow, matches)
+    (findNextJoinRowsFuncName, streamedRow, matches)
   }
 
   /**
@@ -647,7 +650,7 @@ case class SortMergeJoinExec(
     val bufferedInput = ctx.addMutableState("scala.collection.Iterator", "bufferedInput",
       v => s"$v = inputs[1];", forceInline = true)
 
-    val (streamedRow, matches) = genScanner(ctx)
+    val (findNextJoinRowsFuncName, streamedRow, matches) = genScanner(ctx)
 
     // Create variables for row from both sides.
     val (streamedVars, streamedVarDecl) = createStreamedVars(ctx, streamedRow)
@@ -715,7 +718,7 @@ case class SortMergeJoinExec(
          |$numOutput.add(1);
          |${consume(ctx, resultVars)}
        """.stripMargin
-    val findNextJoinRows = s"findNextJoinRows($streamedInput, $bufferedInput)"
+    val findNextJoinRows = s"$findNextJoinRowsFuncName($streamedInput, $bufferedInput)"
     val thisPlan = ctx.addReferenceObj("plan", this)
     val eagerCleanup = s"$thisPlan.cleanupResources();"