diff --git a/classes/data-stores/ActionScheduler_DBStore.php b/classes/data-stores/ActionScheduler_DBStore.php
index 79cdcf38c..78484db13 100644
--- a/classes/data-stores/ActionScheduler_DBStore.php
+++ b/classes/data-stores/ActionScheduler_DBStore.php
@@ -19,8 +19,13 @@ class ActionScheduler_DBStore extends ActionScheduler_Store {
 	 */
 	private $claim_before_date = null;
 
-	/** @var int */
-	protected static $max_args_length = 8000;
+	/**
+	 * The "longtext" field type can store up to 4,294,967,295 (4GB) characters.
+	 * For sanity, allow up to half the length of 4GB (2GB) in the field.
+	 *
+	 * @var int
+	 */
+	protected static $max_args_length = 2147483647; // longtext length (4GB)
 
 	/** @var int */
 	protected static $max_index_length = 191;
diff --git a/classes/schema/ActionScheduler_StoreSchema.php b/classes/schema/ActionScheduler_StoreSchema.php
index 2506f0180..b4fe817bf 100644
--- a/classes/schema/ActionScheduler_StoreSchema.php
+++ b/classes/schema/ActionScheduler_StoreSchema.php
@@ -16,7 +16,7 @@ class ActionScheduler_StoreSchema extends ActionScheduler_Abstract_Schema {
 	/**
 	 * @var int Increment this value to trigger a schema update.
 	 */
-	protected $schema_version = 6;
+	protected $schema_version = 7;
 
 	public function __construct() {
 		$this->tables = [
@@ -31,6 +31,7 @@ public function __construct() {
 	 */
 	public function init() {
 		add_action( 'action_scheduler_before_schema_update', array( $this, 'update_schema_5_0' ), 10, 2 );
+		add_action( 'action_scheduler_before_schema_update', array( $this, 'update_schema_7_0' ), 10, 2 );
 	}
 
 	protected function get_table_definition( $table ) {
@@ -56,7 +57,7 @@ protected function get_table_definition( $table ) {
 				        last_attempt_gmt datetime NULL default '${default_date}',
 				        last_attempt_local datetime NULL default '${default_date}',
 				        claim_id bigint(20) unsigned NOT NULL default '0',
-				        extended_args varchar(8000) DEFAULT NULL,
+				        extended_args longtext,
 				        PRIMARY KEY  (action_id),
 				        KEY hook (hook($max_index_length)),
 				        KEY status (status),
@@ -126,4 +127,24 @@ public function update_schema_5_0( $table, $db_version ) {
 		}
 		// phpcs:enable WordPress.DB.PreparedSQL.InterpolatedNotPrepared
 	}
+
+	/**
+	 * Update the actions table schema, changing `$extended_args` fields to be longtext.
+	 *
+	 * @param string $table Name of table being updated.
+	 * @param string $db_version The existing schema version of the table.
+	 */
+	public function update_schema_7_0( $table, $db_version ) {
+		global $wpdb;
+
+		if ( 'actionscheduler_actions' !== $table || version_compare( $db_version, '7', '>=' ) ) {
+			return;
+		}
+
+		$table_name   = $wpdb->prefix . 'actionscheduler_actions';
+		$table_list   = $wpdb->get_col( "SHOW TABLES LIKE '${table_name}'" );
+		if ( ! empty( $table_list ) ) {
+			$wpdb->query( "ALTER TABLE ${table_name} MODIFY COLUMN extended_args longtext" ); // phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared
+		}
+	}
 }