diff --git a/mysql-test/r/query_cache_notembedded.result b/mysql-test/r/query_cache_notembedded.result
index 16a397f78b6..e773a63525b 100644
--- a/mysql-test/r/query_cache_notembedded.result
+++ b/mysql-test/r/query_cache_notembedded.result
@@ -80,4 +80,18 @@ show status like "Qcache_free_blocks";
 Variable_name	Value
 Qcache_free_blocks	1
 drop table t1, t2, t3, t11, t21;
+CREATE TABLE t1 ( a INT NOT NULL PRIMARY KEY AUTO_INCREMENT ) ENGINE =
+MyISAM;
+LOCK TABLE t1 READ LOCAL;
+INSERT INTO t1 VALUES (), (), ();
+SELECT * FROM t1;
+a
+SELECT * FROM t1;
+a
+1
+2
+3
+SELECT * FROM t1;
+a
+drop table t1;
 set GLOBAL query_cache_size=0;
diff --git a/mysql-test/t/query_cache_notembedded.test b/mysql-test/t/query_cache_notembedded.test
index d29dc10ccae..fd4785ffe95 100644
--- a/mysql-test/t/query_cache_notembedded.test
+++ b/mysql-test/t/query_cache_notembedded.test
@@ -78,4 +78,23 @@ show status like "Qcache_total_blocks";
 show status like "Qcache_free_blocks";
 drop table t1, t2, t3, t11, t21;
 
+#
+# do not use QC if tables locked (BUG#12385)
+#
+connect (root,localhost,root,,test,$MASTER_MYPORT,master.sock);
+connection root;
+CREATE TABLE t1 ( a INT NOT NULL PRIMARY KEY AUTO_INCREMENT ) ENGINE =
+MyISAM;
+LOCK TABLE t1 READ LOCAL;
+connect (root2,localhost,root,,test,$MASTER_MYPORT,master.sock);
+connection root2;
+INSERT INTO t1 VALUES (), (), ();
+connection root;
+SELECT * FROM t1;
+connection root2;
+SELECT * FROM t1;
+connection root;
+SELECT * FROM t1;
+drop table t1;
+
 set GLOBAL query_cache_size=0;
diff --git a/sql/item_strfunc.cc b/sql/item_strfunc.cc
index 52a2dedb67c..b7015b3d6ef 100644
--- a/sql/item_strfunc.cc
+++ b/sql/item_strfunc.cc
@@ -1187,7 +1187,7 @@ String *Item_func_substr_index::val_str(String *str)
       }
     }
     else
-    {					// Start counting at end
+    {
       /*
         Negative index, start counting at the end
       */
diff --git a/sql/sql_cache.cc b/sql/sql_cache.cc
index 366a13d59ba..2dd88f40005 100644
--- a/sql/sql_cache.cc
+++ b/sql/sql_cache.cc
@@ -762,7 +762,7 @@ void Query_cache::store_query(THD *thd, TABLE_LIST *tables_used)
   TABLE_COUNTER_TYPE local_tables;
   ulong tot_length;
   DBUG_ENTER("Query_cache::store_query");
-  if (query_cache_size == 0)
+  if (query_cache_size == 0 || thd->locked_tables)
     DBUG_VOID_RETURN;
   uint8 tables_type= 0;
 
@@ -921,8 +921,8 @@ Query_cache::send_result_to_client(THD *thd, char *sql, uint query_length)
   bool check_tables;
   DBUG_ENTER("Query_cache::send_result_to_client");
 
-  if (query_cache_size == 0 || thd->variables.query_cache_type == 0)
-
+  if (query_cache_size == 0 || thd->locked_tables ||
+      thd->variables.query_cache_type == 0)
     goto err;
 
   /* Check that we haven't forgot to reset the query cache variables */