diff --git a/mysql-test/r/merge.result b/mysql-test/r/merge.result
index eb333cdadb7..33de735d714 100644
--- a/mysql-test/r/merge.result
+++ b/mysql-test/r/merge.result
@@ -801,3 +801,8 @@ CREATE TABLE tm1(a SMALLINT, b SMALLINT, KEY(a)) ENGINE=MERGE UNION=(t1);
 SELECT * FROM tm1;
 ERROR HY000: Unable to open underlying table which is differently defined or of non-MyISAM type or doesn't exist
 DROP TABLE t1, tm1;
+CREATE TABLE t1(c1 INT) ENGINE=MyISAM;
+CREATE TABLE t2(c1 INT) ENGINE=MERGE UNION=(t1);
+INSERT DELAYED INTO t2 VALUES(1);
+ERROR HY000: Table storage engine for 't2' doesn't have this option
+DROP TABLE t1, t2;
diff --git a/mysql-test/t/merge.test b/mysql-test/t/merge.test
index 700a807e62c..f759d20dd80 100644
--- a/mysql-test/t/merge.test
+++ b/mysql-test/t/merge.test
@@ -428,4 +428,13 @@ CREATE TABLE tm1(a SMALLINT, b SMALLINT, KEY(a)) ENGINE=MERGE UNION=(t1);
 SELECT * FROM tm1;
 DROP TABLE t1, tm1;
 
+#
+# Bug#26464 - insert delayed + update + merge = corruption
+#
+CREATE TABLE t1(c1 INT) ENGINE=MyISAM;
+CREATE TABLE t2(c1 INT) ENGINE=MERGE UNION=(t1);
+--error 1031
+INSERT DELAYED INTO t2 VALUES(1);
+DROP TABLE t1, t2;
+
 # End of 4.1 tests
diff --git a/sql/ha_myisammrg.h b/sql/ha_myisammrg.h
index 84eaae04590..84af55b262e 100644
--- a/sql/ha_myisammrg.h
+++ b/sql/ha_myisammrg.h
@@ -37,7 +37,7 @@ class ha_myisammrg: public handler
   {
     return (HA_REC_NOT_IN_SEQ | HA_AUTO_PART_KEY | HA_READ_RND_SAME |
 	    HA_NULL_IN_KEY | HA_CAN_INDEX_BLOBS | HA_FILE_BASED |
-            HA_CAN_INSERT_DELAYED | HA_ANY_INDEX_MAY_BE_UNIQUE);
+            HA_ANY_INDEX_MAY_BE_UNIQUE);
   }
   ulong index_flags(uint inx, uint part, bool all_parts) const
   {