diff --git a/models/asymkey/gpg_key_import.go b/models/asymkey/gpg_key_import.go
index 5b5ef4faba..83881b5c22 100644
--- a/models/asymkey/gpg_key_import.go
+++ b/models/asymkey/gpg_key_import.go
@@ -23,7 +23,7 @@ import "code.gitea.io/gitea/models/db"
 // GPGKeyImport the original import of key
 type GPGKeyImport struct {
 	KeyID   string `xorm:"pk CHAR(16) NOT NULL"`
-	Content string `xorm:"TEXT NOT NULL"`
+	Content string `xorm:"MEDIUMTEXT NOT NULL"`
 }
 
 func init() {
diff --git a/models/migrations/migrations.go b/models/migrations/migrations.go
index 79e8573881..73c44f008a 100644
--- a/models/migrations/migrations.go
+++ b/models/migrations/migrations.go
@@ -457,6 +457,8 @@ var migrations = []Migration{
 	NewMigration("Add actions tables", v1_19.AddActionsTables),
 	// v241 -> v242
 	NewMigration("Add card_type column to project table", v1_19.AddCardTypeToProjectTable),
+	// v242 -> v243
+	NewMigration("Alter gpg_key_import content TEXT field to MEDIUMTEXT", v1_19.AlterPublicGPGKeyImportContentFieldToMediumText),
 }
 
 // GetCurrentDBVersion returns the current db version
diff --git a/models/migrations/v1_19/v242.go b/models/migrations/v1_19/v242.go
new file mode 100644
index 0000000000..517c7767b8
--- /dev/null
+++ b/models/migrations/v1_19/v242.go
@@ -0,0 +1,26 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package v1_19 //nolint
+
+import (
+	"code.gitea.io/gitea/modules/setting"
+
+	"xorm.io/xorm"
+)
+
+// AlterPublicGPGKeyImportContentFieldToMediumText: set GPGKeyImport Content field to MEDIUMTEXT
+func AlterPublicGPGKeyImportContentFieldToMediumText(x *xorm.Engine) error {
+	sess := x.NewSession()
+	defer sess.Close()
+	if err := sess.Begin(); err != nil {
+		return err
+	}
+
+	if setting.Database.UseMySQL {
+		if _, err := sess.Exec("ALTER TABLE `gpg_key_import` CHANGE `content` `content` MEDIUMTEXT"); err != nil {
+			return err
+		}
+	}
+	return sess.Commit()
+}