diff --git a/tests/phpunit/tests/image/functions.php b/tests/phpunit/tests/image/functions.php
index 444d730fdc..cbacec809e 100644
--- a/tests/phpunit/tests/image/functions.php
+++ b/tests/phpunit/tests/image/functions.php
@@ -423,6 +423,8 @@ class Tests_Image_Functions extends WP_UnitTestCase {
 		$test_file = '/tmp/wordpress-gsoc-flyer.pdf';
 		copy( $orig_file, $test_file );
 
+		$this->assertNotWPError( wp_get_image_editor( $test_file ) );
+
 		$attachment_id = $this->factory->attachment->create_object(
 			$test_file,
 			0,
@@ -488,6 +490,8 @@ class Tests_Image_Functions extends WP_UnitTestCase {
 		$test_file = get_temp_dir() . 'wordpress-gsoc-flyer.pdf';
 		copy( $orig_file, $test_file );
 
+		$this->assertNotWPError( wp_get_image_editor( $test_file ) );
+
 		$attachment_id = $this->factory->attachment->create_object(
 			$test_file,
 			0,
@@ -548,6 +552,8 @@ class Tests_Image_Functions extends WP_UnitTestCase {
 		$test_file = '/tmp/wordpress-gsoc-flyer.pdf';
 		copy( $orig_file, $test_file );
 
+		$this->assertNotWPError( wp_get_image_editor( $test_file ) );
+
 		$attachment_id = $this->factory->attachment->create_object(
 			$test_file,
 			0,
@@ -608,6 +614,8 @@ class Tests_Image_Functions extends WP_UnitTestCase {
 		$pdf_path = '/tmp/test.pdf';
 		copy( DIR_TESTDATA . '/images/wordpress-gsoc-flyer.pdf', $pdf_path );
 
+		$this->assertNotWPError( wp_get_image_editor( $pdf_path ) );
+
 		$attachment_id = $this->factory->attachment->create_object(
 			$pdf_path,
 			0,