diff --git a/mysql-test/suite/innodb/r/alter_algorithm,INPLACE.rdiff b/mysql-test/suite/innodb/r/alter_algorithm,INPLACE.rdiff
index a1fa20c2ba1..805ccdb563c 100644
--- a/mysql-test/suite/innodb/r/alter_algorithm,INPLACE.rdiff
+++ b/mysql-test/suite/innodb/r/alter_algorithm,INPLACE.rdiff
@@ -1,6 +1,6 @@
 --- alter_algorithm.result
 +++ alter_algorithm.reject
-@@ -7,44 +7,44 @@
+@@ -7,40 +7,40 @@
  INSERT INTO t1(f1, f2, f3) VALUES(1, 1, 1);
  SELECT @@alter_algorithm;
  @@alter_algorithm
@@ -18,12 +18,6 @@
 -affected rows: 1
 -info: Records: 1  Duplicates: 0  Warnings: 0
 +affected rows: 0
-+info: Records: 0  Duplicates: 0  Warnings: 0
- # Make existing column NON-NULLABLE
- ALTER TABLE t1 MODIFY f3 INT NOT NULL;
--affected rows: 1
--info: Records: 1  Duplicates: 0  Warnings: 0
-+affected rows: 0
 +info: Records: 0  Duplicates: 0  Warnings: 0
  # Drop Stored Column
  ALTER TABLE t1 DROP COLUMN f5;
@@ -64,7 +58,7 @@
  DROP TABLE t1;
  affected rows: 0
  CREATE TABLE t1(f1 INT PRIMARY KEY, f2 INT NOT NULL,
-@@ -57,22 +57,22 @@
+@@ -53,22 +53,22 @@
  FOREIGN KEY fidx(f1) REFERENCES t1(f1))ENGINE=INNODB;
  INSERT INTO t1(f1, f2, f4, f5) VALUES(1, 2, 3, 4);
  ALTER TABLE t1 ADD INDEX idx1(f4), page_compressed=1;
@@ -97,7 +91,7 @@
  DROP TABLE t2, t1;
  affected rows: 0
  CREATE TABLE t1(f1 INT NOT NULL,
-@@ -85,27 +85,27 @@
+@@ -81,27 +81,27 @@
  INSERT INTO t1(f1, f2) VALUES(1, 1);
  # Add column at the end of the table
  ALTER TABLE t1 ADD COLUMN f4 char(100) default 'BIG WALL';
@@ -135,7 +129,7 @@
  # Column length varies
  ALTER TABLE t2 CHANGE f3 f3 VARCHAR(20);
  affected rows: 0
-@@ -113,12 +113,12 @@
+@@ -109,12 +109,12 @@
  SET foreign_key_checks = 0;
  affected rows: 0
  ALTER TABLE t3 ADD FOREIGN KEY fidx(f2) REFERENCES t2(f1);
diff --git a/mysql-test/suite/innodb/r/alter_algorithm,INSTANT.rdiff b/mysql-test/suite/innodb/r/alter_algorithm,INSTANT.rdiff
index 879bba43932..6d2ee160e46 100644
--- a/mysql-test/suite/innodb/r/alter_algorithm,INSTANT.rdiff
+++ b/mysql-test/suite/innodb/r/alter_algorithm,INSTANT.rdiff
@@ -1,6 +1,6 @@
 --- alter_algorithm.result
 +++ alter_algorithm.reject
-@@ -7,44 +7,35 @@
+@@ -7,40 +7,32 @@
  INSERT INTO t1(f1, f2, f3) VALUES(1, 1, 1);
  SELECT @@alter_algorithm;
  @@alter_algorithm
@@ -16,11 +16,6 @@
  ALTER TABLE t1 MODIFY f2 INT;
 -affected rows: 1
 -info: Records: 1  Duplicates: 0  Warnings: 0
-+Got one of the listed errors
- # Make existing column NON-NULLABLE
- ALTER TABLE t1 MODIFY f3 INT NOT NULL;
--affected rows: 1
--info: Records: 1  Duplicates: 0  Warnings: 0
 +Got one of the listed errors
  # Drop Stored Column
  ALTER TABLE t1 DROP COLUMN f5;
@@ -55,7 +50,7 @@
  DROP TABLE t1;
  affected rows: 0
  CREATE TABLE t1(f1 INT PRIMARY KEY, f2 INT NOT NULL,
-@@ -57,22 +48,17 @@
+@@ -53,22 +45,17 @@
  FOREIGN KEY fidx(f1) REFERENCES t1(f1))ENGINE=INNODB;
  INSERT INTO t1(f1, f2, f4, f5) VALUES(1, 2, 3, 4);
  ALTER TABLE t1 ADD INDEX idx1(f4), page_compressed=1;
@@ -83,7 +78,7 @@
  DROP TABLE t2, t1;
  affected rows: 0
  CREATE TABLE t1(f1 INT NOT NULL,
-@@ -85,27 +71,27 @@
+@@ -81,27 +68,27 @@
  INSERT INTO t1(f1, f2) VALUES(1, 1);
  # Add column at the end of the table
  ALTER TABLE t1 ADD COLUMN f4 char(100) default 'BIG WALL';
@@ -121,7 +116,7 @@
  # Column length varies
  ALTER TABLE t2 CHANGE f3 f3 VARCHAR(20);
  affected rows: 0
-@@ -113,12 +99,12 @@
+@@ -109,12 +96,12 @@
  SET foreign_key_checks = 0;
  affected rows: 0
  ALTER TABLE t3 ADD FOREIGN KEY fidx(f2) REFERENCES t2(f1);
diff --git a/mysql-test/suite/innodb/r/alter_algorithm,NOCOPY.rdiff b/mysql-test/suite/innodb/r/alter_algorithm,NOCOPY.rdiff
index 6db0f2af347..c6ce83b5d9f 100644
--- a/mysql-test/suite/innodb/r/alter_algorithm,NOCOPY.rdiff
+++ b/mysql-test/suite/innodb/r/alter_algorithm,NOCOPY.rdiff
@@ -1,6 +1,6 @@
 --- alter_algorithm.result
 +++ alter_algorithm.reject
-@@ -7,44 +7,35 @@
+@@ -7,40 +7,32 @@
  INSERT INTO t1(f1, f2, f3) VALUES(1, 1, 1);
  SELECT @@alter_algorithm;
  @@alter_algorithm
@@ -16,11 +16,6 @@
  ALTER TABLE t1 MODIFY f2 INT;
 -affected rows: 1
 -info: Records: 1  Duplicates: 0  Warnings: 0
-+Got one of the listed errors
- # Make existing column NON-NULLABLE
- ALTER TABLE t1 MODIFY f3 INT NOT NULL;
--affected rows: 1
--info: Records: 1  Duplicates: 0  Warnings: 0
 +Got one of the listed errors
  # Drop Stored Column
  ALTER TABLE t1 DROP COLUMN f5;
@@ -55,7 +50,7 @@
  DROP TABLE t1;
  affected rows: 0
  CREATE TABLE t1(f1 INT PRIMARY KEY, f2 INT NOT NULL,
-@@ -57,22 +48,22 @@
+@@ -53,22 +45,22 @@
  FOREIGN KEY fidx(f1) REFERENCES t1(f1))ENGINE=INNODB;
  INSERT INTO t1(f1, f2, f4, f5) VALUES(1, 2, 3, 4);
  ALTER TABLE t1 ADD INDEX idx1(f4), page_compressed=1;
@@ -88,7 +83,7 @@
  DROP TABLE t2, t1;
  affected rows: 0
  CREATE TABLE t1(f1 INT NOT NULL,
-@@ -85,27 +76,27 @@
+@@ -81,27 +73,27 @@
  INSERT INTO t1(f1, f2) VALUES(1, 1);
  # Add column at the end of the table
  ALTER TABLE t1 ADD COLUMN f4 char(100) default 'BIG WALL';
@@ -126,7 +121,7 @@
  # Column length varies
  ALTER TABLE t2 CHANGE f3 f3 VARCHAR(20);
  affected rows: 0
-@@ -113,12 +104,12 @@
+@@ -109,12 +101,12 @@
  SET foreign_key_checks = 0;
  affected rows: 0
  ALTER TABLE t3 ADD FOREIGN KEY fidx(f2) REFERENCES t2(f1);
diff --git a/mysql-test/suite/innodb/r/alter_algorithm.result b/mysql-test/suite/innodb/r/alter_algorithm.result
index 3d3a7e85444..bcfbe3355f9 100644
--- a/mysql-test/suite/innodb/r/alter_algorithm.result
+++ b/mysql-test/suite/innodb/r/alter_algorithm.result
@@ -17,10 +17,6 @@ info: Records: 1  Duplicates: 0  Warnings: 0
 ALTER TABLE t1 MODIFY f2 INT;
 affected rows: 1
 info: Records: 1  Duplicates: 0  Warnings: 0
-# Make existing column NON-NULLABLE
-ALTER TABLE t1 MODIFY f3 INT NOT NULL;
-affected rows: 1
-info: Records: 1  Duplicates: 0  Warnings: 0
 # Drop Stored Column
 ALTER TABLE t1 DROP COLUMN f5;
 affected rows: 1
diff --git a/mysql-test/suite/innodb/r/innodb-alter-nullable.result b/mysql-test/suite/innodb/r/innodb-alter-nullable.result
index 68ad6762335..1d481cf2bfe 100644
--- a/mysql-test/suite/innodb/r/innodb-alter-nullable.result
+++ b/mysql-test/suite/innodb/r/innodb-alter-nullable.result
@@ -96,8 +96,8 @@ INSERT INTO t3 SET c=NULL;
 SET @old_sql_mode = @@sql_mode;
 SET sql_mode = '';
 ALTER TABLE t1 MODIFY c INT NOT NULL;
-affected rows: 0
-info: Records: 0  Duplicates: 0  Warnings: 1
+affected rows: 1
+info: Records: 1  Duplicates: 0  Warnings: 1
 Warnings:
 Warning	1265	Data truncated for column 'c' at row 1
 ALTER TABLE t2 MODIFY c INT NOT NULL;
@@ -111,10 +111,9 @@ info: Records: 1  Duplicates: 0  Warnings: 1
 Warnings:
 Warning	1265	Data truncated for column 'c' at row 1
 SET sql_mode = @old_sql_mode;
-# MDEV-18819 FIXME: Wrong result g=NULL
 SELECT * FROM t1;
 c	g
-0	NULL
+0	0
 SELECT * FROM t2;
 c	v
 0	0
@@ -137,8 +136,8 @@ INSERT INTO t1 SET c=NULL;
 INSERT INTO t2 SET c=NULL;
 INSERT INTO t3 SET c=NULL;
 ALTER IGNORE TABLE t1 MODIFY c INT NOT NULL;
-affected rows: 0
-info: Records: 0  Duplicates: 0  Warnings: 1
+affected rows: 1
+info: Records: 1  Duplicates: 0  Warnings: 1
 Warnings:
 Warning	1265	Data truncated for column 'c' at row 1
 ALTER IGNORE TABLE t2 MODIFY c INT NOT NULL;
@@ -151,10 +150,9 @@ affected rows: 1
 info: Records: 1  Duplicates: 0  Warnings: 1
 Warnings:
 Warning	1265	Data truncated for column 'c' at row 1
-# MDEV-18819 FIXME: Wrong result g=NULL
 SELECT * FROM t1;
 c	g
-0	NULL
+0	0
 SELECT * FROM t2;
 c	v
 0	0
@@ -186,12 +184,11 @@ UPDATE t1 SET c=0;
 UPDATE t2 SET c=0;
 UPDATE t3 SET c=0;
 ALTER TABLE t1 MODIFY c INT NOT NULL;
-affected rows: 0
-info: Records: 0  Duplicates: 0  Warnings: 0
+affected rows: 1
+info: Records: 1  Duplicates: 0  Warnings: 0
 ALTER TABLE t2 MODIFY c INT NOT NULL;
 affected rows: 0
 info: Records: 0  Duplicates: 0  Warnings: 0
-# MDEV-18819 FIXME: This should not require ALGORITHM=COPY.
 ALTER TABLE t3 MODIFY c INT NOT NULL;
 affected rows: 1
 info: Records: 1  Duplicates: 0  Warnings: 0
diff --git a/mysql-test/suite/innodb/t/alter_algorithm.test b/mysql-test/suite/innodb/t/alter_algorithm.test
index 7cb706e865a..d410a15154d 100644
--- a/mysql-test/suite/innodb/t/alter_algorithm.test
+++ b/mysql-test/suite/innodb/t/alter_algorithm.test
@@ -31,10 +31,6 @@ ALTER TABLE t1 ADD COLUMN col1 INT NOT NULL,DROP PRIMARY KEY,ADD PRIMARY KEY(col
 --error $error_code
 ALTER TABLE t1 MODIFY f2 INT;
 
---echo # Make existing column NON-NULLABLE
---error $error_code
-ALTER TABLE t1 MODIFY f3 INT NOT NULL;
-
 --echo # Drop Stored Column
 --error $error_code
 ALTER TABLE t1 DROP COLUMN f5;
diff --git a/mysql-test/suite/innodb/t/innodb-alter-nullable.test b/mysql-test/suite/innodb/t/innodb-alter-nullable.test
index 9e6f5df2bc9..af13a12ab41 100644
--- a/mysql-test/suite/innodb/t/innodb-alter-nullable.test
+++ b/mysql-test/suite/innodb/t/innodb-alter-nullable.test
@@ -104,7 +104,6 @@ ALTER TABLE t2 MODIFY c INT NOT NULL;
 ALTER TABLE t3 MODIFY c INT NOT NULL;
 --disable_info
 SET sql_mode = @old_sql_mode;
---echo # MDEV-18819 FIXME: Wrong result g=NULL
 SELECT * FROM t1;
 SELECT * FROM t2;
 SELECT * FROM t3;
@@ -123,7 +122,6 @@ ALTER IGNORE TABLE t1 MODIFY c INT NOT NULL;
 ALTER IGNORE TABLE t2 MODIFY c INT NOT NULL;
 ALTER IGNORE TABLE t3 MODIFY c INT NOT NULL;
 --disable_info
---echo # MDEV-18819 FIXME: Wrong result g=NULL
 SELECT * FROM t1;
 SELECT * FROM t2;
 SELECT * FROM t3;
@@ -151,7 +149,6 @@ UPDATE t3 SET c=0;
 --enable_info
 ALTER TABLE t1 MODIFY c INT NOT NULL;
 ALTER TABLE t2 MODIFY c INT NOT NULL;
---echo # MDEV-18819 FIXME: This should not require ALGORITHM=COPY.
 ALTER TABLE t3 MODIFY c INT NOT NULL;
 --disable_info
 SELECT * FROM t1;
diff --git a/sql/sql_table.cc b/sql/sql_table.cc
index 8eb0b078bd1..bb22e9a9f34 100644
--- a/sql/sql_table.cc
+++ b/sql/sql_table.cc
@@ -6733,7 +6733,7 @@ static bool fill_alter_inplace_info(THD *thd, TABLE *table, bool varchar,
           }
 
           if (field->vcol_info->is_in_partitioning_expr() ||
-              field->flags & PART_KEY_FLAG)
+              field->flags & PART_KEY_FLAG || field->stored_in_db())
           {
             if (value_changes)
               ha_alter_info->handler_flags|= ALTER_COLUMN_VCOL;