diff --git a/README.md b/README.md
index 7d365f7..c3655ad 100644
--- a/README.md
+++ b/README.md
@@ -28,6 +28,8 @@ type Map = {
 
 ## Usage
 
+`npm install --save redux-combine-containers`
+
 Let's say we have 2 react-redux containers, `document-viewer` and `document-list`. These module can be used standalone with their own state, actions and views.  
 We want to create a new `document-index` container, using these two submodules, with a single state tree, without duplicating code.
 
diff --git a/__tests__/index.test.js b/__tests__/index.test.js
index 6c4e901..f817b77 100644
--- a/__tests__/index.test.js
+++ b/__tests__/index.test.js
@@ -1,7 +1,7 @@
 //@flow
 
 import { fromJS } from "immutable";
-import { getCombinedReducer, getCombinedDispatchToProps, getCombinedStateToProps } from "../esm/index.js";
+import { getCombinedReducer, getCombinedDispatchToProps, getCombinedStateToProps } from "../index.js";
 
 test("getCombinedReducer", () => {
     const reducers = {
diff --git a/esm/index.js b/esm/index.js
index 304aa7e..da7ab30 100644
--- a/esm/index.js
+++ b/esm/index.js
@@ -1,43 +1,28 @@
-//@flow
+import _Object$assign from '@babel/runtime/core-js/object/assign';
+import _Object$entries from '@babel/runtime/core-js/object/entries';
+
 /**
  * Helpers to combine multiple redux containers props object (mapStateToProps/mapDispatchToProps pairs)
  * into a single props object.
  * Each individual container is identified by a key in the final object.
  */
 
- /**
-  * mapStateToProps / mapDispatch to props pair.
-  */
-export type CombinedMapper = {
-    mapStateToProps: (state: Map) => any,
-    mapDispatchToProps: (dispatch: any, props: any) => any
-};
+/**
+ * mapStateToProps / mapDispatch to props pair.
+ */
 
 /**
  * Simple definition of immutable.Map
  */
-type Map = {
-    get: (key: any) => any,
-    set: (key: any, value: any) => Map
-};
-
-type ReduxAction = {
-    type: string,
-    data?: any
-};
 
 /**
  * Naive object reduce implementation to avoid dependencies
  */
-const reduceMappers = (mappers: {[key: string]: any}, fn: (accumulator: any, value: any) => any, initialValue: any) => {
-    return Object.entries(mappers).reduce(
-        (acc, pair: Array<any>) => {
-            return fn.call(null, acc, pair[1], pair[0]);
-        },
-        initialValue
-    );
+const reduceMappers = (mappers, fn, initialValue) => {
+  return _Object$entries(mappers).reduce((acc, pair) => {
+    return fn.call(null, acc, pair[1], pair[0]);
+  }, initialValue);
 };
-
 /**
  * This is essentially `combineReducers`: each sub-reducer gets his sub-state tree only.
  * 
@@ -45,22 +30,19 @@ const reduceMappers = (mappers: {[key: string]: any}, fn: (accumulator: any, val
  * 
  * If a reducer has a `global` key, this reducer will have access to the complete state tree.
  */
-export const getCombinedReducer = (reducers: {[key: string]: (state: Map) => Map}) => {
-    return (state: Map, action: ReduxAction): Map => {
-        return reduceMappers(
-            reducers,
-            (curState: Map, reducer: (state: Map) => Map, key: string) => {
-                if (key === "global") {
-                    return reducer(curState, action);
-                }
-                return curState.set(key, reducer(curState.get(key), action));
-            },
-            state
-        );
-    };
-};
 
 
+const getCombinedReducer = reducers => {
+  return (state, action) => {
+    return reduceMappers(reducers, (curState, reducer, key) => {
+      if (key === "global") {
+        return reducer(curState, action);
+      }
+
+      return curState.set(key, reducer(curState.get(key), action));
+    }, state);
+  };
+};
 /**
  * The returned object (the final state tree) is a combination of `globalProps` with each sub-state trees.
  * 
@@ -69,25 +51,20 @@ export const getCombinedReducer = (reducers: {[key: string]: (state: Map) => Map
  * 
  * `globalProps` are at the root of the state tree.
  */
-export const getCombinedStateToProps = (mappers: {[key: string]: CombinedMapper}, state: Map, globalProps: any) => {
-    return reduceMappers(
-        mappers,
-        (props: any, mapper: any, key: string) => {
-            props[ key ] = props[ key ] ? props[ key ] : {};
-            props[ key ] = Object.assign(props[ key ], mapper.mapStateToProps(state.get(key)));
-            return props;
-        },
-        globalProps
-    );
+
+const getCombinedStateToProps = (mappers, state, globalProps) => {
+  return reduceMappers(mappers, (props, mapper, key) => {
+    props[key] = props[key] ? props[key] : {};
+    props[key] = _Object$assign(props[key], mapper.mapStateToProps(state.get(key)));
+    return props;
+  }, globalProps);
+};
+const getCombinedDispatchToProps = (mappers, dispatch, props, defaultActions) => {
+  return reduceMappers(mappers, (props, mapper, key) => {
+    props[key] = props[key] ? props[key] : {};
+    props[key] = _Object$assign(props[key], mapper.mapDispatchToProps(dispatch));
+    return props;
+  }, defaultActions);
 };
-export const getCombinedDispatchToProps = (mappers: {[key: string]: CombinedMapper}, dispatch: () => void, props: any, defaultActions: any) => {
-    return reduceMappers(
-        mappers,
-        (props: any, mapper: any, key: string) => {
-            props[ key ] = props[ key ] ? props[ key ] : {};
-            props[ key ] = Object.assign(props[ key ], mapper.mapDispatchToProps(dispatch));
-            return props;
-        },
-        defaultActions
-    );
-};
\ No newline at end of file
+
+export { getCombinedReducer, getCombinedStateToProps, getCombinedDispatchToProps };
diff --git a/index.js b/index.js
new file mode 100644
index 0000000..304aa7e
--- /dev/null
+++ b/index.js
@@ -0,0 +1,93 @@
+//@flow
+/**
+ * Helpers to combine multiple redux containers props object (mapStateToProps/mapDispatchToProps pairs)
+ * into a single props object.
+ * Each individual container is identified by a key in the final object.
+ */
+
+ /**
+  * mapStateToProps / mapDispatch to props pair.
+  */
+export type CombinedMapper = {
+    mapStateToProps: (state: Map) => any,
+    mapDispatchToProps: (dispatch: any, props: any) => any
+};
+
+/**
+ * Simple definition of immutable.Map
+ */
+type Map = {
+    get: (key: any) => any,
+    set: (key: any, value: any) => Map
+};
+
+type ReduxAction = {
+    type: string,
+    data?: any
+};
+
+/**
+ * Naive object reduce implementation to avoid dependencies
+ */
+const reduceMappers = (mappers: {[key: string]: any}, fn: (accumulator: any, value: any) => any, initialValue: any) => {
+    return Object.entries(mappers).reduce(
+        (acc, pair: Array<any>) => {
+            return fn.call(null, acc, pair[1], pair[0]);
+        },
+        initialValue
+    );
+};
+
+/**
+ * This is essentially `combineReducers`: each sub-reducer gets his sub-state tree only.
+ * 
+ * Example: "document" reducer : `state.set("document", reducers.document(state.get("document"), action));`
+ * 
+ * If a reducer has a `global` key, this reducer will have access to the complete state tree.
+ */
+export const getCombinedReducer = (reducers: {[key: string]: (state: Map) => Map}) => {
+    return (state: Map, action: ReduxAction): Map => {
+        return reduceMappers(
+            reducers,
+            (curState: Map, reducer: (state: Map) => Map, key: string) => {
+                if (key === "global") {
+                    return reducer(curState, action);
+                }
+                return curState.set(key, reducer(curState.get(key), action));
+            },
+            state
+        );
+    };
+};
+
+
+/**
+ * The returned object (the final state tree) is a combination of `globalProps` with each sub-state trees.
+ * 
+ * Each submodule has it's key in the state tree.  
+ * `finalProps.document = mappers.document.mapStateToProps(state)`
+ * 
+ * `globalProps` are at the root of the state tree.
+ */
+export const getCombinedStateToProps = (mappers: {[key: string]: CombinedMapper}, state: Map, globalProps: any) => {
+    return reduceMappers(
+        mappers,
+        (props: any, mapper: any, key: string) => {
+            props[ key ] = props[ key ] ? props[ key ] : {};
+            props[ key ] = Object.assign(props[ key ], mapper.mapStateToProps(state.get(key)));
+            return props;
+        },
+        globalProps
+    );
+};
+export const getCombinedDispatchToProps = (mappers: {[key: string]: CombinedMapper}, dispatch: () => void, props: any, defaultActions: any) => {
+    return reduceMappers(
+        mappers,
+        (props: any, mapper: any, key: string) => {
+            props[ key ] = props[ key ] ? props[ key ] : {};
+            props[ key ] = Object.assign(props[ key ], mapper.mapDispatchToProps(dispatch));
+            return props;
+        },
+        defaultActions
+    );
+};
\ No newline at end of file
diff --git a/rollup.config.js b/rollup.config.js
index fb95991..502da08 100644
--- a/rollup.config.js
+++ b/rollup.config.js
@@ -3,15 +3,18 @@ import replace from "rollup-plugin-replace";
 
 
 export default {
-    input: "./esm/index.js",
+    input: "./index.js",
     output: [
         {
             file: "./cjs/index.js",
             format: "cjs"
+        },{
+            file: "./esm/index.js",
+            format: "es"
         }
     ],
     watch: {
-        include: ["./esm/index.js"]
+        include: ["./index.js"]
     },
     plugins: [
         replace({