diff --git a/.github/workflows/wp-tests.yml b/.github/workflows/wp-tests.yml
index 0dfbedaa..b3e42d05 100644
--- a/.github/workflows/wp-tests.yml
+++ b/.github/workflows/wp-tests.yml
@@ -50,6 +50,9 @@ jobs:
             -   name: Build schema.json
                 run: npm install && npm run build:schema
 
+            -   name: Install Subversion
+                run: sudo apt-get update && sudo apt-get install --no-install-recommends --yes subversion
+
             -   name: Install WordPress test setup
                 run: bash tests/bin/install-wp-tests.sh wordpress_test root password 127.0.0.1:${{ job.services.mysql.ports[3306] }} latest
 
diff --git a/tests/plugin/test-liberate-controller.php b/tests/plugin/test-liberate-controller.php
index ec577b7e..138f366f 100644
--- a/tests/plugin/test-liberate-controller.php
+++ b/tests/plugin/test-liberate-controller.php
@@ -68,7 +68,9 @@ protected function setUp(): void {
 
 	protected function tearDown(): void {
 		wp_delete_post( $this->inserted_post_id, true );
-		wp_delete_post( $this->transformed_post_id, true );
+		if ( 0 < $this->transformed_post_id ) {
+			wp_delete_post( $this->transformed_post_id, true );
+		}
 	}
 
 	public function testGetStoragePostType() {