diff --git a/tests/files/issue-171.png b/tests/files/issue-171.png
new file mode 100644
index 00000000..bf83f52b
Binary files /dev/null and b/tests/files/issue-171.png differ
diff --git a/tests/regression.rs b/tests/regression.rs
index ef7ee0bf..1b20edee 100644
--- a/tests/regression.rs
+++ b/tests/regression.rs
@@ -611,3 +611,15 @@ fn issue_167() {
         BitDepth::Eight,
     );
 }
+
+#[test]
+fn issue_171() {
+    test_it_converts(
+        "tests/files/issue-171.png",
+        None,
+        ColorType::Grayscale,
+        BitDepth::Eight,
+        ColorType::Grayscale,
+        BitDepth::Eight,
+    );
+}