diff --git a/src/Init/Data/Hashable.lean b/src/Init/Data/Hashable.lean
index 931725006d..3f81ec033e 100644
--- a/src/Init/Data/Hashable.lean
+++ b/src/Init/Data/Hashable.lean
@@ -27,6 +27,12 @@ instance [Hashable α] : Hashable (Option α) where
 instance [Hashable α] : Hashable (List α) where
   hash as := as.foldl (fun r a => mixHash r (hash a)) 7
 
+instance : Hashable UInt8 where
+  hash n := n.toUInt64
+
+instance : Hashable UInt16 where
+  hash n := n.toUInt64
+
 instance : Hashable UInt32 where
   hash n := n.toUInt64
 
diff --git a/tests/lean/run/sarray.lean b/tests/lean/run/sarray.lean
index 191eeb9d6d..ebfafc00ee 100644
--- a/tests/lean/run/sarray.lean
+++ b/tests/lean/run/sarray.lean
@@ -34,4 +34,4 @@ def tst3 (n : Nat) (expected : UInt32) : IO Unit := do
 
 set_option trace.compiler.ir.result true in
 def computeByteHash (bytes : ByteArray) :=
-   bytes.foldl (init := 1723) fun h b => mixHash h (hash b.toNat)
+   bytes.foldl (init := 1723) fun h b => mixHash h (hash b)