diff --git a/mysql-test/r/ndb_basic.result b/mysql-test/r/ndb_basic.result
index fab10867acd..75ccc6cd39e 100644
--- a/mysql-test/r/ndb_basic.result
+++ b/mysql-test/r/ndb_basic.result
@@ -667,6 +667,12 @@ counter	datavalue
 57	newval
 58	newval
 drop table t1;
+create table t1 (a int primary key auto_increment) engine = ndb;
+insert into t1() values (),(),(),(),(),(),(),(),(),(),(),();
+insert into t1(a) values (20),(28);
+insert into t1() values (),(),(),(),(),(),(),(),(),(),(),();
+insert into t1() values (21), (22);
+drop table t1;
 CREATE TABLE t1 ( b INT ) PACK_KEYS = 0 ENGINE = ndb;
 select * from t1;
 b
diff --git a/mysql-test/t/ndb_basic.test b/mysql-test/t/ndb_basic.test
index 8fda2ede948..70fbfbfe733 100644
--- a/mysql-test/t/ndb_basic.test
+++ b/mysql-test/t/ndb_basic.test
@@ -606,6 +606,21 @@ select * from t1 order by counter;
 
 drop table t1;
 
+#
+# bug#27437
+connection con1;
+create table t1 (a int primary key auto_increment) engine = ndb;
+insert into t1() values (),(),(),(),(),(),(),(),(),(),(),();
+connection con2;
+insert into t1(a) values (20),(28);
+connection con1;
+insert into t1() values (),(),(),(),(),(),(),(),(),(),(),();
+connection con2;
+insert into t1() values (21), (22);
+connection con1;
+
+drop table t1;
+
 #
 # BUG#14514 Creating table with packed key fails silently
 #
diff --git a/ndb/src/kernel/blocks/dblqh/Dblqh.hpp b/ndb/src/kernel/blocks/dblqh/Dblqh.hpp
index 00367a7aa9d..4474d226a27 100644
--- a/ndb/src/kernel/blocks/dblqh/Dblqh.hpp
+++ b/ndb/src/kernel/blocks/dblqh/Dblqh.hpp
@@ -2059,6 +2059,9 @@ public:
     Uint8 simpleRead;
     Uint8 seqNoReplica;
     Uint8 tcNodeFailrec;
+#ifdef VM_TRACE
+    Uint8 tupkeyref;
+#endif
   }; /* p2c: size = 280 bytes */
   
   typedef Ptr<TcConnectionrec> TcConnectionrecPtr;
diff --git a/ndb/src/kernel/blocks/dblqh/DblqhMain.cpp b/ndb/src/kernel/blocks/dblqh/DblqhMain.cpp
index 9944adf4ede..f531383e4bd 100644
--- a/ndb/src/kernel/blocks/dblqh/DblqhMain.cpp
+++ b/ndb/src/kernel/blocks/dblqh/DblqhMain.cpp
@@ -2765,6 +2765,12 @@ void Dblqh::execTUPKEYREF(Signal* signal)
   tcConnectptr.i = tupKeyRef->userRef;
   terrorCode = tupKeyRef->errorCode;
   ptrCheckGuard(tcConnectptr, ctcConnectrecFileSize, tcConnectionrec);
+
+#ifdef VM_TRACE
+  ndbrequire(tcConnectptr.p->tupkeyref == 0);
+  tcConnectptr.p->tupkeyref = 1;
+#endif
+
   switch (tcConnectptr.p->transactionState) {
   case TcConnectionrec::WAIT_TUP:
     jam();
@@ -3330,6 +3336,10 @@ void Dblqh::seizeTcrec()
   locTcConnectptr.p->tcTimer = cLqhTimeOutCount;
   locTcConnectptr.p->tableref = RNIL;
   locTcConnectptr.p->savePointId = 0;
+#ifdef VM_TRACE
+  locTcConnectptr.p->tupkeyref = 0;
+#endif
+
   cfirstfreeTcConrec = nextTc;
   tcConnectptr = locTcConnectptr;
   locTcConnectptr.p->connectState = TcConnectionrec::CONNECTED;
@@ -5860,6 +5870,10 @@ void Dblqh::completeUnusualLab(Signal* signal)
 void Dblqh::releaseTcrec(Signal* signal, TcConnectionrecPtr locTcConnectptr) 
 {
   jam();
+#ifdef VM_TRACE
+  locTcConnectptr.p->tupkeyref = 0;
+#endif
+
   locTcConnectptr.p->tcTimer = 0;
   locTcConnectptr.p->transactionState = TcConnectionrec::TC_NOT_CONNECTED;
   locTcConnectptr.p->nextTcConnectrec = cfirstfreeTcConrec;
@@ -5882,6 +5896,9 @@ void Dblqh::releaseTcrec(Signal* signal, TcConnectionrecPtr locTcConnectptr)
 void Dblqh::releaseTcrecLog(Signal* signal, TcConnectionrecPtr locTcConnectptr) 
 {
   jam();
+#ifdef VM_TRACE
+  locTcConnectptr.p->tupkeyref = 0;
+#endif
   locTcConnectptr.p->tcTimer = 0;
   locTcConnectptr.p->transactionState = TcConnectionrec::TC_NOT_CONNECTED;
   locTcConnectptr.p->nextTcConnectrec = cfirstfreeTcConrec;
diff --git a/ndb/src/kernel/blocks/dbtup/DbtupExecQuery.cpp b/ndb/src/kernel/blocks/dbtup/DbtupExecQuery.cpp
index 72ef9a274ec..28f3b987e7b 100644
--- a/ndb/src/kernel/blocks/dbtup/DbtupExecQuery.cpp
+++ b/ndb/src/kernel/blocks/dbtup/DbtupExecQuery.cpp
@@ -1138,7 +1138,11 @@ Dbtup::updateStartLab(Signal* signal,
                                 regOperPtr->attrinbufLen);
   } else {
     jam();
-    retValue = interpreterStartLab(signal, pagePtr, regOperPtr->pageOffset);
+    if (interpreterStartLab(signal, pagePtr, regOperPtr->pageOffset) == -1)
+    {
+      jam();
+      return -1;
+    }
   }//if
 
   if (retValue == -1) {