diff --git a/phoenix-core/src/it/java/org/apache/phoenix/end2end/ConcurrentMutationsExtendedIT.java b/phoenix-core/src/it/java/org/apache/phoenix/end2end/ConcurrentMutationsExtendedIT.java
index da009d29f0c..659c8c9f42c 100644
--- a/phoenix-core/src/it/java/org/apache/phoenix/end2end/ConcurrentMutationsExtendedIT.java
+++ b/phoenix-core/src/it/java/org/apache/phoenix/end2end/ConcurrentMutationsExtendedIT.java
@@ -44,7 +44,9 @@
 import java.io.IOException;
 import java.sql.Connection;
 import java.sql.DriverManager;
+import java.sql.PreparedStatement;
 import java.sql.SQLException;
+import java.sql.Statement;
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Map;
@@ -471,6 +473,66 @@ public void testLockUntilMVCCAdvanced() throws Exception {
         assertEquals(1, actualRowCount);
     }
 
+
+    @Test
+    public void testConcurrentUpsertAndSchemaUpdation() throws Exception {
+        final String tableName = "testConcurrentUpsertAndSchemaUpdation" + generateUniqueName();
+        Connection conn = DriverManager.getConnection(getUrl());
+        conn.createStatement().execute("CREATE TABLE " + tableName
+                + "(k VARCHAR PRIMARY KEY, v1 INTEGER, v2 INTEGER ) COLUMN_ENCODED_BYTES = 0");
+        Runnable r1 = () -> {
+            Connection conn1 = null;
+            try {
+                Properties props = new Properties();
+                String url = QueryUtil.getConnectionUrl(props, config, "client1");
+                conn1 = DriverManager.getConnection(url);
+                for (int i = 0; i < 10; i++) {
+                    String pk = "foo" + i;
+                    int column1 = i;
+                    int column2 = i + 20;
+                    String dml = "UPSERT INTO " + tableName + " VALUES (?, ?, ?)";
+                    PreparedStatement stmt = conn1.prepareStatement(dml);
+                    stmt.setString(1, pk);
+                    stmt.setInt(2, column1);
+                    stmt.setInt(3, column2);
+                    stmt.execute();
+                    // Sleep for 5 seconds.
+                    Thread.sleep(5000);
+                }
+                conn1.commit();
+            } catch (Exception e) {
+                e.printStackTrace();
+            } finally {
+                try {
+                    conn1.close();
+                } catch (SQLException sqle) {
+                    sqle.printStackTrace();
+                }
+            }
+        };
+        Runnable r2 = () -> {
+
+            try {
+                // Sleep for 10 seconds so that we generate atleast 2 mutations with old schema
+                Thread.sleep(10000);
+                Properties props = new Properties();
+                String url2 = QueryUtil.getConnectionUrl(props, config, "client2");
+                Connection conn2 = DriverManager.getConnection(url2);
+                conn2.createStatement()
+                        .execute("ALTER TABLE " + tableName + " DROP COLUMN V2");
+                conn2.commit();
+            } catch (Exception e) {
+                e.printStackTrace();
+            }
+        };
+        Thread t1 = new Thread(r1);
+        t1.start();
+        Thread t2 = new Thread(r2);
+        t2.start();
+        t1.join();
+        t2.join();
+    }
+
     public static class DelayingRegionObserver extends SimpleRegionObserver {
         private volatile boolean lockedTableRow;
 
diff --git a/phoenix-core/src/main/java/org/apache/phoenix/execute/MutationState.java b/phoenix-core/src/main/java/org/apache/phoenix/execute/MutationState.java
index ebb3524f765..549c8848e8d 100644
--- a/phoenix-core/src/main/java/org/apache/phoenix/execute/MutationState.java
+++ b/phoenix-core/src/main/java/org/apache/phoenix/execute/MutationState.java
@@ -1867,6 +1867,7 @@ public void commit() throws SQLException {
             boolean retryCommit = false;
             SQLException sqlE = null;
             try {
+                // validate last ddl timestamps
                 send();
                 txMutations = this.txMutations;
                 sendSuccessful = true;