diff --git a/mysql-test/r/heap.result b/mysql-test/r/heap.result
index 29bdfcbef7a..ddf675e2f73 100644
--- a/mysql-test/r/heap.result
+++ b/mysql-test/r/heap.result
@@ -731,3 +731,10 @@ SELECT COUNT(*) FROM t1 WHERE c=REPEAT('a',256);
 COUNT(*)
 2
 DROP TABLE t1;
+CREATE TABLE t1(c1 VARCHAR(100), c2 INT) ENGINE=MEMORY;
+INSERT INTO t1 VALUES('', 0);
+ALTER TABLE t1 MODIFY c1 VARCHAR(101);
+SELECT c2 FROM t1;
+c2
+0
+DROP TABLE t1;
diff --git a/mysql-test/t/heap.test b/mysql-test/t/heap.test
index 624597cd8d7..b47a5fc2033 100644
--- a/mysql-test/t/heap.test
+++ b/mysql-test/t/heap.test
@@ -471,3 +471,12 @@ SELECT COUNT(*) FROM t1 WHERE c=REPEAT('a',256);
 DROP TABLE t1;
 
 # End of 5.0 tests
+
+#
+# BUG#26080 - Memory Storage engine not working properly
+#
+CREATE TABLE t1(c1 VARCHAR(100), c2 INT) ENGINE=MEMORY;
+INSERT INTO t1 VALUES('', 0);
+ALTER TABLE t1 MODIFY c1 VARCHAR(101);
+SELECT c2 FROM t1;
+DROP TABLE t1;
diff --git a/storage/heap/ha_heap.cc b/storage/heap/ha_heap.cc
index cf11c9923eb..f2caa7e6d18 100644
--- a/storage/heap/ha_heap.cc
+++ b/storage/heap/ha_heap.cc
@@ -703,9 +703,10 @@ bool ha_heap::check_if_incompatible_data(HA_CREATE_INFO *info,
 					 uint table_changes)
 {
   /* Check that auto_increment value was not changed */
-  if ((table_changes != IS_EQUAL_YES &&
-       info->used_fields & HA_CREATE_USED_AUTO) &&
-      info->auto_increment_value != 0)
+  if ((info->used_fields & HA_CREATE_USED_AUTO &&
+       info->auto_increment_value != 0) ||
+      table_changes == IS_EQUAL_NO ||
+      table_changes & IS_EQUAL_PACK_LENGTH) // Not implemented yet
     return COMPATIBLE_DATA_NO;
   return COMPATIBLE_DATA_YES;
 }