diff --git a/rebar.config b/rebar.config
index b6aca1b..f484fc7 100644
--- a/rebar.config
+++ b/rebar.config
@@ -5,6 +5,11 @@
 {edoc_opts, [{dialyzer_specs, all}]}.
 {validate_app_modules, true}.
 
+{erl_first_files, [
+                   "src/msgpack_ext.erl"
+                  ]}.
+
+
 %% {port_sources, ["c_src/*.c"]}.
 %% {port_env, [
 %% 	     %% Make sure to set -fPIC when compiling leveldb