diff --git a/mysql-test/main/delayed.result b/mysql-test/main/delayed.result
index 73e1ed40c6a58..30d8fe99ccd6e 100644
--- a/mysql-test/main/delayed.result
+++ b/mysql-test/main/delayed.result
@@ -420,3 +420,11 @@ CREATE TABLE t1 (c0 INT,UNIQUE (c0) USING HASH) ENGINE=MYISAM;
 INSERT DELAYED INTO t1 VALUES (0);
 INSERT DELAYED INTO t1 VALUES (0);
 DROP TABLE t1;
+#
+# MDEV-38726: Assertion `table->default_field != dfield_ptr' failed in
+# bool parse_vcol_defs(THD *, MEM_ROOT *, TABLE *, bool *,
+# vcol_init_mode)
+#
+CREATE TABLE t_38726 (a TIMESTAMP ON UPDATE CURRENT_TIMESTAMP()) ENGINE=MYISAM;
+INSERT DELAYED INTO t_38726 VALUES ();
+DROP TABLE t_38726;
diff --git a/mysql-test/main/delayed.test b/mysql-test/main/delayed.test
index 0ed009825f70f..a578a76dbd4f8 100644
--- a/mysql-test/main/delayed.test
+++ b/mysql-test/main/delayed.test
@@ -632,3 +632,13 @@ INSERT DELAYED INTO t1 VALUES (0);
 DROP TABLE t1;
 
 --enable_view_protocol
+
+--echo #
+--echo # MDEV-38726: Assertion `table->default_field != dfield_ptr' failed in
+--echo # bool parse_vcol_defs(THD *, MEM_ROOT *, TABLE *, bool *,
+--echo # vcol_init_mode)
+--echo #
+
+CREATE TABLE t_38726 (a TIMESTAMP ON UPDATE CURRENT_TIMESTAMP()) ENGINE=MYISAM;
+INSERT DELAYED INTO t_38726 VALUES ();
+DROP TABLE t_38726;
diff --git a/sql/sql_insert.cc b/sql/sql_insert.cc
index d0aa138abd633..2cbd71c0935b2 100644
--- a/sql/sql_insert.cc
+++ b/sql/sql_insert.cc
@@ -3132,7 +3132,21 @@ TABLE *Delayed_insert::get_local_table(THD* client_thd)
     (*field)->invisible= (*org_field)->invisible;
     (*field)->orig_table= copy;			// Remove connection
     (*field)->move_field_offset(adjust_ptrs);	// Point at copy->record[0]
-    (*field)->flags|= ((*org_field)->flags & LONG_UNIQUE_HASH_FIELD);
+
+    /*
+      Option 1: Copy all flags from the original field (though I assume there
+                is some reason we don't want to do this? As it wasn't done
+                before. I can't find why that is though.)
+    */
+    (*field)->flags|= ((*org_field)->flags);
+
+    /*
+      Option 2: Only copy the missing flag identified by the assert
+
+    (*field)->flags|=
+        ((*org_field)->flags & (LONG_UNIQUE_HASH_FIELD | ON_UPDATE_NOW_FLAG));
+    */
+
     (*field)->invisible= (*org_field)->invisible;
     if (memdup_vcol(client_thd, (*field)->vcol_info))
       goto error;