diff --git a/storage/innobase/row/row0log.cc b/storage/innobase/row/row0log.cc
index 3a7d3dd5d86..4d541b779a6 100644
--- a/storage/innobase/row/row0log.cc
+++ b/storage/innobase/row/row0log.cc
@@ -1461,11 +1461,6 @@ void row_log_table_blob_alloc(
     const dict_col_t *new_col = log->table->get_col(col_no);
     ut_ad(new_col->mtype == col->mtype);
 
-    /* Assert that prtype matches except for nullability. */
-    ut_ad(!((new_col->prtype ^ col->prtype) & ~DATA_NOT_NULL));
-    ut_ad(!((new_col->prtype ^ dfield_get_type(dfield)->prtype) &
-            ~DATA_NOT_NULL));
-
     if (new_col->prtype == col->prtype) {
       continue;
     }
diff --git a/mysql-test/suite/innodb/t/bug_report_online_rebuild_redundant_char_corruption.test b/mysql-test/suite/innodb/t/bug_report_online_rebuild_redundant_char_corruption.test
new file mode 100644
index 00000000000..75f1e10dc78
--- /dev/null
+++ b/mysql-test/suite/innodb/t/bug_report_online_rebuild_redundant_char_corruption.test
@@ -0,0 +1,31 @@
+--source include/have_debug.inc
+--source include/have_debug_sync.inc
+
+CREATE TABLE bug_report_online_rebuild_redundant_char_corruption (
+  id INT NOT NULL PRIMARY KEY,
+  c CHAR(32) NOT NULL DEFAULT ''
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb3 ROW_FORMAT=DYNAMIC;
+
+INSERT INTO bug_report_online_rebuild_redundant_char_corruption
+  VALUES (1, 'before alter');
+
+connect (con1,localhost,root,,);
+
+connection con1;
+SET DEBUG_SYNC =
+  'alter_table_inplace_after_lock_downgrade SIGNAL alter_ready WAIT_FOR dml_done';
+--send ALTER TABLE bug_report_online_rebuild_redundant_char_corruption CONVERT TO CHARACTER SET utf8mb4, ROW_FORMAT=REDUNDANT, ALGORITHM=INPLACE, LOCK=NONE
+
+connection default;
+SET DEBUG_SYNC='now WAIT_FOR alter_ready';
+INSERT INTO bug_report_online_rebuild_redundant_char_corruption
+  VALUES (2, 'during alter');
+SET DEBUG_SYNC='now SIGNAL dml_done';
+
+connection con1;
+--reap
+
+connection default;
+SET DEBUG_SYNC='RESET';
+CHECK TABLE bug_report_online_rebuild_redundant_char_corruption;
+DROP TABLE bug_report_online_rebuild_redundant_char_corruption;