diff --git a/.github/workflows/oxipng.yml b/.github/workflows/oxipng.yml
index bbb421e9..4c4d10af 100644
--- a/.github/workflows/oxipng.yml
+++ b/.github/workflows/oxipng.yml
@@ -55,6 +55,7 @@ jobs:
 
     env:
       CARGO_BUILD_TARGET: ${{ matrix.target }}
+      RUSTFLAGS: -Zlocation-detail=none
 
     steps:
       - name: Checkout source
diff --git a/Cargo.toml b/Cargo.toml
index 17dd2612..1808a1f1 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -95,8 +95,6 @@ path = "src/lib.rs"
 opt-level = 2
 
 [profile.release]
-lto = "thin"
+lto = "fat"
 strip = "symbols"
-
-[profile.dev.package.bitvec]
-opt-level = 3
+panic = "abort"
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/files/zopfli_mode.png b/tests/files/zopfli_mode.png
index 3f9bdb1a..82ca1f07 100644
Binary files a/tests/files/zopfli_mode.png and b/tests/files/zopfli_mode.png differ
diff --git a/tests/flags.rs b/tests/flags.rs
index 53d84a22..baf0ea69 100644
--- a/tests/flags.rs
+++ b/tests/flags.rs
@@ -686,9 +686,9 @@ fn zopfli_mode() {
         input,
         &output,
         &opts,
-        RGB,
+        INDEXED,
         BitDepth::Eight,
-        RGB,
+        INDEXED,
         BitDepth::Eight,
     );
 }
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(