diff --git a/tests/common.rs b/tests/common.rs
new file mode 100644
index 0000000..cc1eff1
--- /dev/null
+++ b/tests/common.rs
@@ -0,0 +1,12 @@
+#[allow(unused)]
+pub fn hash<const N: usize>(px: [u8; N]) -> u8 {
+    let r = px[0];
+    let g = px[1];
+    let b = px[2];
+    let a = if N >= 4 { px[3] } else { 0xff };
+    let rm = r.wrapping_mul(3);
+    let gm = g.wrapping_mul(5);
+    let bm = b.wrapping_mul(7);
+    let am = a.wrapping_mul(11);
+    rm.wrapping_add(gm).wrapping_add(bm).wrapping_add(am) % 64
+}
diff --git a/tests/test_chunks.rs b/tests/test_chunks.rs
index beeffe4..391ba53 100644
--- a/tests/test_chunks.rs
+++ b/tests/test_chunks.rs
@@ -1,3 +1,5 @@
+mod common;
+
 use bytemuck::{cast_slice, Pod};
 
 use qoi_fast::consts::{
@@ -6,18 +8,7 @@ use qoi_fast::consts::{
 };
 use qoi_fast::{decode_to_vec, encode_to_vec};
 
-#[allow(unused)]
-fn hash<const N: usize>(px: [u8; N]) -> u8 {
-    let r = px[0];
-    let g = px[1];
-    let b = px[2];
-    let a = if N >= 4 { px[3] } else { 0xff };
-    let rm = r.wrapping_mul(3);
-    let gm = g.wrapping_mul(5);
-    let bm = b.wrapping_mul(7);
-    let am = a.wrapping_mul(11);
-    rm.wrapping_add(gm).wrapping_add(bm).wrapping_add(am) % 64
-}
+use self::common::hash;
 
 fn test_chunk<P, E, const N: usize>(pixels: P, expected: E)
 where