diff --git a/lib/protobuf/dsl.ex b/lib/protobuf/dsl.ex
index 68cfb853..4474c1cb 100644
--- a/lib/protobuf/dsl.ex
+++ b/lib/protobuf/dsl.ex
@@ -57,6 +57,9 @@ defmodule Protobuf.DSL do
       end)
       if !found, do: raise "The first enum value must be zero in proto3"
     end
+    mapping = Enum.reduce(props, %{}, fn {_, %{fnum: fnum, name_atom: name_atom}}, acc ->
+      Map.put(acc, name_atom, fnum)
+    end)
     Enum.map(props, fn {_, %{fnum: fnum, name_atom: name_atom}} ->
       quote do
         def value(unquote(name_atom)), do: unquote(fnum)
@@ -70,7 +73,11 @@ defmodule Protobuf.DSL do
       quote do
         def key(unquote(fnum)), do: unquote(name_atom)
       end
-    end)
+    end) ++ [
+      quote do
+        def mapping(), do: unquote(Macro.escape(mapping))
+      end
+    ]
   end
 
   defp def_enum_functions(_), do: nil
diff --git a/test/protobuf/dsl_test.exs b/test/protobuf/dsl_test.exs
index 85c30388..eef8079e 100644
--- a/test/protobuf/dsl_test.exs
+++ b/test/protobuf/dsl_test.exs
@@ -137,6 +137,7 @@ defmodule Protobuf.DSLTest do
     assert TestMsg.EnumFoo.key(1) == :A
     assert TestMsg.EnumFoo.key(2) == :B
     assert TestMsg.EnumFoo.key(4) == :C
+    assert TestMsg.EnumFoo.mapping() == %{UNKNOWN: 0, A: 1, B: 2, C: 4}
 
     assert %FieldProps{fnum: 11, type: {:enum, TestMsg.EnumFoo}, wire_type: 0} =
              Foo.__message_props__().field_props[11]