diff --git a/tests/files/grayscale_alpha_8_should_be_grayscale_trns_1.png b/tests/files/grayscale_alpha_8_should_be_grayscale_trns_1.png
new file mode 100644
index 00000000..3434291f
Binary files /dev/null and b/tests/files/grayscale_alpha_8_should_be_grayscale_trns_1.png differ
diff --git a/tests/reduction.rs b/tests/reduction.rs
index 8a1a1e34..7176ccca 100644
--- a/tests/reduction.rs
+++ b/tests/reduction.rs
@@ -916,6 +916,18 @@ fn grayscale_alpha_8_should_be_grayscale_trns_8() {
     );
 }
 
+#[test]
+fn grayscale_alpha_8_should_be_grayscale_trns_1() {
+    test_it_converts(
+        "tests/files/grayscale_alpha_8_should_be_grayscale_trns_1.png",
+        true,
+        GRAYSCALE_ALPHA,
+        BitDepth::Eight,
+        GRAYSCALE,
+        BitDepth::One,
+    );
+}
+
 #[test]
 fn small_files() {
     test_it_converts(