diff --git a/src/Init/Data/ByteArray/Basic.lean b/src/Init/Data/ByteArray/Basic.lean
index bf7e897915..13a33ad96c 100644
--- a/src/Init/Data/ByteArray/Basic.lean
+++ b/src/Init/Data/ByteArray/Basic.lean
@@ -20,12 +20,20 @@ universe u
 
 namespace ByteArray
 
-deriving instance BEq for ByteArray
+@[extern "lean_sarray_dec_eq"]
+def beq (lhs rhs : @& ByteArray) : Bool :=
+  lhs.data == rhs.data
+
+instance : BEq ByteArray where
+  beq := beq
 
 attribute [ext] ByteArray
 
-instance : DecidableEq ByteArray :=
-  fun _ _ => decidable_of_decidable_of_iff ByteArray.ext_iff.symm
+@[extern "lean_sarray_dec_eq"]
+def decEq (lhs rhs : @& ByteArray) : Decidable (lhs = rhs) :=
+  decidable_of_decidable_of_iff ByteArray.ext_iff.symm
+
+instance : DecidableEq ByteArray := decEq
 
 instance : Inhabited ByteArray where
   default := empty
diff --git a/src/include/lean/lean.h b/src/include/lean/lean.h
index 80ef067831..4b47665bc4 100644
--- a/src/include/lean/lean.h
+++ b/src/include/lean/lean.h
@@ -976,6 +976,13 @@ static inline void lean_sarray_set_size(u_lean_obj_arg o, size_t sz) {
 }
 static inline uint8_t* lean_sarray_cptr(lean_object * o) { return lean_to_sarray(o)->m_data; }
 
+LEAN_EXPORT bool lean_sarray_eq_cold(b_lean_obj_arg a1, b_lean_obj_arg a2);
+static inline bool lean_sarray_eq(b_lean_obj_arg a1, b_lean_obj_arg a2) {
+    assert(lean_sarray_elem_size(a1) == lean_sarray_elem_size(a2));
+    return a1 == a2 || (lean_sarray_size(a1) == lean_sarray_size(a2) && lean_sarray_eq_cold(a1, a2));
+}
+static inline uint8_t lean_sarray_dec_eq(b_lean_obj_arg a1, b_lean_obj_arg a2) { return lean_sarray_eq(a1, a2); }
+
 /* Remark: expand sarray API after we add better support in the compiler */
 
 /* ByteArray (special case of Array of Scalars) */
diff --git a/src/runtime/object.cpp b/src/runtime/object.cpp
index 4b1e1e63c3..fb5a4484ee 100644
--- a/src/runtime/object.cpp
+++ b/src/runtime/object.cpp
@@ -2078,6 +2078,11 @@ extern "C" LEAN_EXPORT bool lean_string_eq_cold(b_lean_obj_arg s1, b_lean_obj_ar
     return std::memcmp(lean_string_cstr(s1), lean_string_cstr(s2), lean_string_size(s1)) == 0;
 }
 
+extern "C" LEAN_EXPORT bool lean_sarray_eq_cold(b_lean_obj_arg a1, b_lean_obj_arg a2) {
+    size_t len = lean_sarray_elem_size(a1) * lean_sarray_size(a1);
+    return std::memcmp(lean_sarray_cptr(a1), lean_sarray_cptr(a2), len) == 0;
+}
+
 bool string_eq(object * s1, char const * s2) {
     if (lean_string_size(s1) != strlen(s2) + 1)
         return false;
diff --git a/tests/elab/bytearray_eq.lean b/tests/elab/bytearray_eq.lean
new file mode 100644
index 0000000000..ee51d6d183
--- /dev/null
+++ b/tests/elab/bytearray_eq.lean
@@ -0,0 +1,59 @@
+module
+
+/-! test native equality on ByteArray  -/
+
+def mk (xs : Array UInt8) : ByteArray := ⟨xs⟩
+
+
+/-- info: true -/
+#guard_msgs in
+#eval mk #[] == mk #[]
+/-- info: true -/
+#guard_msgs in
+#eval mk #[1, 2, 3, 4, 5] == mk #[1, 2, 3, 4, 5]
+
+/-- info: true -/
+#guard_msgs in
+#eval mk #[1] != mk #[]
+/-- info: true -/
+#guard_msgs in
+#eval mk #[] != mk #[1]
+/-- info: true -/
+#guard_msgs in
+#eval mk #[1, 2, 3, 4, 5] != mk #[0, 2, 3, 4, 5]
+/-- info: true -/
+#guard_msgs in
+#eval mk #[0, 2, 3, 4, 5] != mk #[1, 2, 3, 4, 5]
+/-- info: true -/
+#guard_msgs in
+#eval mk #[1, 2, 3, 4, 5] != mk #[1, 2, 3, 0, 5]
+/-- info: true -/
+#guard_msgs in
+#eval mk #[1, 2, 3, 0, 5] != mk #[1, 2, 3, 4, 5]
+
+
+/-- info: true -/
+#guard_msgs in
+#eval mk #[] = mk #[]
+/-- info: true -/
+#guard_msgs in
+#eval mk #[1, 2, 3, 4, 5] = mk #[1, 2, 3, 4, 5]
+
+/-- info: true -/
+#guard_msgs in
+#eval mk #[1] ≠ mk #[]
+/-- info: true -/
+#guard_msgs in
+#eval mk #[] ≠ mk #[1]
+/-- info: true -/
+#guard_msgs in
+#eval mk #[1, 2, 3, 4, 5] ≠ mk #[0, 2, 3, 4, 5]
+/-- info: true -/
+#guard_msgs in
+#eval mk #[0, 2, 3, 4, 5] ≠ mk #[1, 2, 3, 4, 5]
+/-- info: true -/
+#guard_msgs in
+#eval mk #[1, 2, 3, 4, 5] ≠ mk #[1, 2, 3, 0, 5]
+/-- info: true -/
+#guard_msgs in
+#eval mk #[1, 2, 3, 0, 5] ≠ mk #[1, 2, 3, 4, 5]