diff --git a/models/migrations/v141.go b/models/migrations/v141.go
index b5824ecd4..ab05698b8 100644
--- a/models/migrations/v141.go
+++ b/models/migrations/v141.go
@@ -12,7 +12,7 @@ import (
 
 func addKeepActivityPrivateUserColumn(x *xorm.Engine) error {
 	type User struct {
-		KeepActivityPrivate bool
+		KeepActivityPrivate bool `xorm:"NOT NULL DEFAULT false"`
 	}
 
 	if err := x.Sync2(new(User)); err != nil {
diff --git a/models/models.go b/models/models.go
index f12a4e8b3..4e3d1b8ff 100644
--- a/models/models.go
+++ b/models/models.go
@@ -15,12 +15,14 @@ import (
 
 	"code.gitea.io/gitea/modules/setting"
 
-	// Needed for the MySQL driver
-	_ "github.com/go-sql-driver/mysql"
+	"xorm.io/builder"
 	"xorm.io/xorm"
 	"xorm.io/xorm/names"
 	"xorm.io/xorm/schemas"
 
+	// Needed for the MySQL driver
+	_ "github.com/go-sql-driver/mysql"
+
 	// Needed for the Postgresql driver
 	_ "github.com/lib/pq"
 
@@ -312,6 +314,13 @@ func DumpDatabase(filePath string, dbType string) error {
 		tbs = append(tbs, t)
 	}
 
+	// temporary fix for v1.13.x (https://github.com/go-gitea/gitea/issues/14069)
+	if _, err := x.Where(builder.IsNull{"keep_activity_private"}).
+		Cols("keep_activity_private").
+		Update(User{KeepActivityPrivate: false}); err != nil {
+		return err
+	}
+
 	type Version struct {
 		ID      int64 `xorm:"pk autoincr"`
 		Version int64