diff --git a/tests/files/issue-133.png b/tests/files/issue-133.png
deleted file mode 100644
index 0d3eb871..00000000
Binary files a/tests/files/issue-133.png and /dev/null differ
diff --git a/tests/regression.rs b/tests/regression.rs
index cc5284b6..570853bf 100644
--- a/tests/regression.rs
+++ b/tests/regression.rs
@@ -315,21 +315,6 @@ fn issue_129() {
     );
 }
 
-#[test]
-fn issue_133() {
-    let input = "tests/files/issue-133.png";
-    let (output, mut opts) = get_opts(Path::new(input));
-    opts.optimize_alpha = true;
-    test_it_converts(
-        input,
-        Some((output, opts)),
-        RGBA,
-        BitDepth::Eight,
-        RGBA,
-        BitDepth::Eight,
-    );
-}
-
 #[test]
 fn issue_140() {
     test_it_converts(