diff --git a/inc/limitations/class-limit-site-templates.php b/inc/limitations/class-limit-site-templates.php
index 18441650..8fafb34b 100644
--- a/inc/limitations/class-limit-site-templates.php
+++ b/inc/limitations/class-limit-site-templates.php
@@ -221,7 +221,8 @@ public function get_available_site_templates() {
 			if (self::BEHAVIOR_AVAILABLE === $site_settings->behavior ||
 				self::BEHAVIOR_PRE_SELECTED === $site_settings->behavior ||
 				self::MODE_DEFAULT === $this->mode) {
-				$available[] = $site_id;
+				// Convert to integer to match type used in validation (absint)
+				$available[] = absint($site_id);
 			}
 		}
 
@@ -248,7 +249,8 @@ public function get_pre_selected_site_template() {
 			$site_settings = (object) $site_settings;
 
 			if (self::BEHAVIOR_PRE_SELECTED === $site_settings->behavior) {
-				$pre_selected_site_template = $site_id;
+				// Convert to integer to match type used in validation (absint)
+				$pre_selected_site_template = absint($site_id);
 			}
 		}
 
diff --git a/tests/WP_Ultimo/Objects/Limitations_Test.php b/tests/WP_Ultimo/Objects/Limitations_Test.php
index 9fba84a5..9c94683d 100644
--- a/tests/WP_Ultimo/Objects/Limitations_Test.php
+++ b/tests/WP_Ultimo/Objects/Limitations_Test.php
@@ -910,4 +910,42 @@ public function test_checkout_plan_plus_addon_preserves_templates(): void {
 		// Disk space should be additive
 		$this->assertEquals(600, $limits->disk_space->get_limit(), 'Disk space should be summed');
 	}
+
+	/**
+	 * Test that get_available_site_templates returns integers, not strings.
+	 *
+	 * Regression test for issue #351: When template IDs are stored as string keys
+	 * in the limit array, they must be converted to integers for proper comparison
+	 * in the Site_Template validation rule.
+	 */
+	public function test_available_site_templates_returns_integers(): void {
+
+		$limitations = new Limitations([
+			'site_templates' => [
+				'enabled' => true,
+				'mode'    => 'choose_available_templates',
+				'limit'   => [
+					'123' => ['behavior' => 'available'],
+					'456' => ['behavior' => 'pre_selected'],
+					'789' => ['behavior' => 'not_available'],
+				],
+			],
+		]);
+
+		$available = $limitations->site_templates->get_available_site_templates();
+
+		// Should return integers, not strings
+		$this->assertContains(123, $available, 'Template 123 should be in available array as integer');
+		$this->assertContains(456, $available, 'Template 456 should be in available array as integer');
+		$this->assertNotContains(789, $available, 'Template 789 should not be available');
+
+		// Verify strict type checking
+		foreach ($available as $template_id) {
+			$this->assertIsInt($template_id, 'All template IDs should be integers');
+		}
+
+		// Verify in_array works with strict comparison
+		$this->assertTrue(in_array(123, $available, true), 'in_array with strict=true should find integer 123');
+		$this->assertTrue(in_array(456, $available, true), 'in_array with strict=true should find integer 456');
+	}
 }