diff --git a/jamcodec/base.py b/jamcodec/base.py
index 2bbaf9b..9a4cccb 100644
--- a/jamcodec/base.py
+++ b/jamcodec/base.py
@@ -115,6 +115,13 @@ def __eq__(self, other):
             return False
         return self.data == other.data
 
+
+    def __lt__(self, other):
+        return self.data < other.data
+
+    def __gt__(self, other):
+        return self.data > other.data
+
     def __len__(self):
         return len(self.data)
 
diff --git a/jamcodec/types.py b/jamcodec/types.py
index 160e209..ce6cbda 100644
--- a/jamcodec/types.py
+++ b/jamcodec/types.py
@@ -977,8 +977,8 @@ def encode(self, value: Union[typing.Mapping, list]) -> JamBytes:
             # Convert to list
             value = value.items()
 
-        # Sort Map by keys
-        value = sorted(value, key=lambda x: x[0])
+        # Sort Map by keys and then values
+        value = sorted(value)
 
         # Encode length of Vec
         data = VarInt64.encode(len(value))
diff --git a/test/test_map.py b/test/test_map.py
index f6344a6..80bc915 100644
--- a/test/test_map.py
+++ b/test/test_map.py
@@ -56,6 +56,25 @@ def test_map_encode_list(self):
             data
         )
 
+    def test_map_encode_sort_key_values(self):
+        obj = Map(U32, U32).new()
+        value = [
+            (2, 1),
+            (2, 2),
+            (1, 2),
+            (1, 1)
+        ]
+
+        data = obj.encode(value)
+
+        self.assertEqual(
+            JamBytes(
+                "0x040100000001000000010000000200000002000000010000000200000002000000"
+            ),
+            data
+        )
+
+
     def test_map_decode(self):
         obj = Map(U32, Bytes).new()