diff --git a/mysql-test/mysql-test-run.pl b/mysql-test/mysql-test-run.pl
index 2de7c507dc3..5d9e42fa7d7 100755
--- a/mysql-test/mysql-test-run.pl
+++ b/mysql-test/mysql-test-run.pl
@@ -2487,7 +2487,7 @@ sub ndbcluster_start_install ($) {
     else
     {
       $ndb_no_ord=32;
-      $ndb_con_op=5000;
+      $ndb_con_op=10000;
       $ndb_dmem="20M";
       $ndb_imem="1M";
       $ndb_pbmem="4M";
diff --git a/mysql-test/r/ndb_row_format.result b/mysql-test/r/ndb_row_format.result
index 6db289c75aa..ae165d87c5c 100644
--- a/mysql-test/r/ndb_row_format.result
+++ b/mysql-test/r/ndb_row_format.result
@@ -37,3 +37,29 @@ ROW_FORMAT=DYNAMIC
 ENGINE=NDB;
 ForceVarPart: 1
 DROP TABLE t1;
+create table t1 (a int auto_increment primary key, b varchar(1000)) engine = ndb;
+insert into t1(b) values ('0123456789');
+insert into t1(b) select b from t1;
+insert into t1(b) select b from t1;
+insert into t1(b) select b from t1;
+insert into t1(b) select b from t1;
+insert into t1(b) select b from t1;
+insert into t1(b) select b from t1;
+insert into t1(b) select b from t1;
+insert into t1(b) select b from t1;
+insert into t1(b) select b from t1;
+insert into t1(b) select b from t1;
+select count(*) from t1;
+count(*)
+1024
+begin;
+update t1 set b = concat(b,b);
+update t1 set b = concat(b,b);
+update t1 set b = concat(b,b);
+update t1 set b = concat(b,b);
+update t1 set b = concat(b,b);
+rollback;
+select count(*),b from t1 group by b;
+count(*)	b
+1024	0123456789
+drop table t1;
diff --git a/mysql-test/t/ndb_row_format.test b/mysql-test/t/ndb_row_format.test
index 9668d8ea515..b1582cbe339 100644
--- a/mysql-test/t/ndb_row_format.test
+++ b/mysql-test/t/ndb_row_format.test
@@ -60,3 +60,27 @@ CREATE TABLE t1
   ENGINE=NDB;
 --exec $NDB_TOOLS_DIR/ndb_desc --no-defaults -d test t1 | grep ForceVarPart
 DROP TABLE t1;
+
+# test of bug
+create table t1 (a int auto_increment primary key, b varchar(1000)) engine = ndb;
+insert into t1(b) values ('0123456789');
+insert into t1(b) select b from t1;
+insert into t1(b) select b from t1;
+insert into t1(b) select b from t1;
+insert into t1(b) select b from t1;
+insert into t1(b) select b from t1;
+insert into t1(b) select b from t1;
+insert into t1(b) select b from t1;
+insert into t1(b) select b from t1;
+insert into t1(b) select b from t1;
+insert into t1(b) select b from t1;
+select count(*) from t1;
+begin;
+update t1 set b = concat(b,b);
+update t1 set b = concat(b,b);
+update t1 set b = concat(b,b);
+update t1 set b = concat(b,b);
+update t1 set b = concat(b,b);
+rollback;
+select count(*),b from t1 group by b;
+drop table t1;
diff --git a/storage/ndb/src/kernel/blocks/dbtup/DbtupExecQuery.cpp b/storage/ndb/src/kernel/blocks/dbtup/DbtupExecQuery.cpp
index ce337afb20b..69b2d6d116e 100644
--- a/storage/ndb/src/kernel/blocks/dbtup/DbtupExecQuery.cpp
+++ b/storage/ndb/src/kernel/blocks/dbtup/DbtupExecQuery.cpp
@@ -2846,6 +2846,12 @@ Dbtup::handle_size_change_after_update(KeyReqStruct* req_struct,
     if (unlikely(realloc_var_part(regFragPtr, regTabPtr, pagePtr, 
 				  refptr, alloc, needed)))
       return -1;
+
+    if (regTabPtr->m_bits & Tablerec::TR_Checksum) 
+    {
+      jam();
+      setChecksum(org, regTabPtr);
+    }
   }
   req_struct->m_tuple_ptr->m_header_bits = copy_bits;
   return 0;