diff --git a/src/module/module-collection.js b/src/module/module-collection.js
index a68f05a51..16febe4a1 100644
--- a/src/module/module-collection.js
+++ b/src/module/module-collection.js
@@ -53,6 +53,14 @@ export default class ModuleCollection {
 
     parent.removeChild(key)
   }
+
+  isRegistered (path) {
+    const parent = this.get(path.slice(0, -1))
+    const key = path[path.length - 1]
+
+    return parent.hasChild(key)
+  }
+
 }
 
 function update (path, targetModule, newModule) {
diff --git a/src/module/module.js b/src/module/module.js
index e856333d0..6256af96f 100644
--- a/src/module/module.js
+++ b/src/module/module.js
@@ -30,6 +30,10 @@ export default class Module {
     return this._children[key]
   }
 
+  hasChild (key) {
+    return key in this._children
+  }
+
   update (rawModule) {
     this._rawModule.namespaced = rawModule.namespaced
     if (rawModule.actions) {
diff --git a/src/store.js b/src/store.js
index 55edd9ea9..544a5175b 100644
--- a/src/store.js
+++ b/src/store.js
@@ -185,6 +185,16 @@ export class Store {
     resetStore(this)
   }
 
+  hasModule (path) {
+    if (typeof path === 'string') path = [path]
+
+    if (process.env.NODE_ENV !== 'production') {
+      assert(Array.isArray(path), `module path must be a string or an Array.`)
+    }
+
+    return this._modules.isRegistered(path)
+  }
+
   hotUpdate (newOptions) {
     this._modules.update(newOptions)
     resetStore(this, true)
diff --git a/test/unit/modules.spec.js b/test/unit/modules.spec.js
index bc8fa2247..a57e3d1c7 100644
--- a/test/unit/modules.spec.js
+++ b/test/unit/modules.spec.js
@@ -80,6 +80,17 @@ describe('Modules', () => {
       store.commit('a/foo')
       expect(mutationSpy).toHaveBeenCalled()
     })
+    it('dynamic module existance test', () => {
+      const store = new Vuex.Store({
+      })
+
+      store.registerModule('bonjour', {
+      })
+
+      expect(store.hasModule('bonjour')).toBe(true)
+      store.unregisterModule('bonjour')
+      expect(store.hasModule('bonjour')).toBe(false)
+    })
 
     it('dynamic module registration preserving hydration', () => {
       const store = new Vuex.Store({})