diff --git a/Makefile b/Makefile
index 76ac4b2..812fe5a 100644
--- a/Makefile
+++ b/Makefile
@@ -31,3 +31,7 @@ dialyzer: compile
 
 doc:
 	./rebar skip_deps=true doc
+
+purity:	compile
+	if [ ! -d purity ]; then mkdir purity; fi
+	purity -v -m -s purity/stats -o purity/results --top-funs purity/top_functions --apps apps/of_switch/ebin deps/*/ebin
diff --git a/rebar.config b/rebar.config
index c558e97..f0f6cce 100644
--- a/rebar.config
+++ b/rebar.config
@@ -1,7 +1,8 @@
 {require_otp_vsn, "R15B"}.
 
 {erl_opts, [fail_on_warning,
-            {parse_transform, lager_transform}]}.
+            {parse_transform, lager_transform},
+	    debug_info]}.
 
 {sub_dirs, [
             "apps/of_switch",