diff --git a/iceberg/iceberg-handler/src/test/java/org/apache/iceberg/mr/hive/TestHiveIcebergMerge.java b/iceberg/iceberg-handler/src/test/java/org/apache/iceberg/mr/hive/TestHiveIcebergMerge.java
new file mode 100644
index 000000000000..f4c738127733
--- /dev/null
+++ b/iceberg/iceberg-handler/src/test/java/org/apache/iceberg/mr/hive/TestHiveIcebergMerge.java
@@ -0,0 +1,92 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.apache.iceberg.mr.hive;
+
+import java.util.List;
+import org.apache.hadoop.hive.ql.parse.SemanticException;
+import org.apache.iceberg.PartitionSpec;
+import org.apache.iceberg.Schema;
+import org.apache.iceberg.data.Record;
+import org.apache.iceberg.mr.TestHelper;
+import org.apache.iceberg.relocated.com.google.common.base.Throwables;
+import org.apache.iceberg.types.Types;
+import org.junit.Assert;
+import org.junit.Test;
+
+import static org.apache.iceberg.types.Types.NestedField.optional;
+
+/**
+ * Tests Merge Related SQL features.
+ */
+public class TestHiveIcebergMerge extends HiveIcebergStorageHandlerWithEngineBase {
+
+  static final Schema SCHEMA = new Schema(
+      optional(1, "a", Types.IntegerType.get()),
+      optional(2, "b", Types.IntegerType.get(), "This is first name")
+  );
+
+  static final List<Record> TGT_RECORDS = TestHelper.RecordsBuilder.newInstance(SCHEMA)
+      .add(0, 1)
+      .add(9, 9)
+      .build();
+
+
+  @Override
+  protected void validateTestParams() {
+  }
+
+  @Test
+  public void testMergeIntoOnClauseColumnsNoAssignedTables() {
+    testTables.createTable(shell, "tgt", SCHEMA,
+        PartitionSpec.unpartitioned(), fileFormat, TGT_RECORDS, formatVersion);
+    shell.executeStatement("alter table default.tgt set tblproperties('write.merge.mode'='copy-on-write')");
+    shell.executeStatement("drop table if exists default.src");
+    shell.executeStatement("create table default.src (a int, b int) stored as orc");
+    shell.executeStatement("use default");
+    String sql = "MERGE INTO tgt using src on a= src.a when matched then update set b=10";
+    try {
+      shell.executeStatement(sql);
+      Assert.assertFalse(true); // place we should not touch
+    } catch (Throwable ex) {
+      Throwable cause = Throwables.getRootCause(ex);
+      Assert.assertTrue(cause instanceof SemanticException);
+    }
+  }
+
+  @Test
+  public void testMergeIntoOnClauseColumns() {
+    testTables.createTable(shell, "tgt", SCHEMA,
+            PartitionSpec.unpartitioned(), fileFormat, TGT_RECORDS, formatVersion);
+    shell.executeStatement("alter table default.tgt set tblproperties('write.merge.mode'='copy-on-write')");
+    shell.executeStatement("drop table if exists default.src");
+    shell.executeStatement("create table default.src (a int, b int) stored as orc");
+    shell.executeStatement("insert into table default.src select 0, 10");
+    shell.executeStatement("use default");
+    shell.executeStatement("merge into tgt using src on tgt.a = src.a when matched then update set b=src.b");
+    List<Object[]> objects = shell.executeStatement("SELECT * FROM tgt ORDER BY a");
+    Assert.assertEquals(2, objects.size());
+    List<Record> expected = TestHelper.RecordsBuilder.newInstance(SCHEMA)
+            .add(0, 10)
+            .add(9, 9)
+            .build();
+    HiveIcebergTestUtils.validateData(expected,
+            HiveIcebergTestUtils.valueForRow(SCHEMA, objects), 0);
+  }
+}
diff --git a/ql/src/java/org/apache/hadoop/hive/ql/parse/MergeSemanticAnalyzer.java b/ql/src/java/org/apache/hadoop/hive/ql/parse/MergeSemanticAnalyzer.java
index 4987384fbc02..020cdb79b6bd 100644
--- a/ql/src/java/org/apache/hadoop/hive/ql/parse/MergeSemanticAnalyzer.java
+++ b/ql/src/java/org/apache/hadoop/hive/ql/parse/MergeSemanticAnalyzer.java
@@ -130,7 +130,15 @@ WHEN NOT MATCHED THEN INSERT VALUES (source.a2, source.b2)
         .sourceName(sourceName)
         .sourceAlias(getSourceAlias(source, sourceName))
         .onClauseAsText(onClauseAsText);
-
+     
+    OnClauseAnalyzer oca = new OnClauseAnalyzer(onClause, targetTable, targetAlias,
+            conf, onClauseAsText);
+    oca.analyze();
+    // unresolved columns are not allowed in the on clause to avoid wrong results
+    if (!oca.unresolvedColumns.isEmpty()) {
+      throw new SemanticException("UnResolvedColumns exist: " + String.join(",", oca.unresolvedColumns) +
+              ". We should assign a table name to each column in the ON clause like tbl.col.");
+    }
     int whenClauseBegins = 3;
     boolean hasHint = false;
     // query hint
@@ -159,12 +167,7 @@ WHEN NOT MATCHED THEN INSERT VALUES (source.a2, source.b2)
     for (ASTNode whenClause : whenClauses) {
       switch (getWhenClauseOperation(whenClause).getType()) {
       case HiveParser.TOK_INSERT:
-        numInsertClauses++;
-
-        OnClauseAnalyzer oca = new OnClauseAnalyzer(onClause, targetTable, targetAlias,
-          conf, onClauseAsText);
-        oca.analyze();
-        
+        numInsertClauses++;       
         mergeStatementBuilder.addWhenClause(
             handleInsert(whenClause, oca.getPredicate(), targetTable))
           .onClausePredicate(oca.getPredicate());