diff --git a/ext/image/test.php b/ext/image/test.php
index 996b5516..0bb36eef 100644
--- a/ext/image/test.php
+++ b/ext/image/test.php
@@ -4,12 +4,20 @@ class ImageTest extends ShimmieWebTestCase {
 		$this->log_in_as_user();
 		$image_id = $this->post_image("ext/simpletest/data/pbx_screenshot.jpg", "test");
 
+		# test collision
+		$this->post_image("ext/simpletest/data/pbx_screenshot.jpg", "test");
+		$this->assert_text("already has hash");
+
 		$this->get_page("user/test");
 		$this->assert_text("Images uploaded: 1");
 		$this->click("Images uploaded");
 		$this->assert_title("Image $image_id: test");
 		$this->log_out();
 
+		# test that serving manually doesn't cause errors
+		$this->get_page("image/$image_id/moo.jpg");
+		$this->get_page("thumb/$image_id/moo.jpg");
+
 		$this->log_in_as_admin();
 		$this->delete_image($image_id);
 		$this->log_out();