diff --git a/src/createStore.js b/src/createStore.js
index d4a6ad9fd3..b6a1840e22 100644
--- a/src/createStore.js
+++ b/src/createStore.js
@@ -234,7 +234,7 @@ export default function createStore(reducer, preloadedState, enhancer) {
        * emission of values from the observable.
        */
       subscribe(observer) {
-        if (typeof observer !== 'object') {
+        if (typeof observer !== 'object' || observer === null) {
           throw new TypeError('Expected the observer to be an object.')
         }
 
diff --git a/test/createStore.spec.js b/test/createStore.spec.js
index d11e389e6e..eee7a752c9 100644
--- a/test/createStore.spec.js
+++ b/test/createStore.spec.js
@@ -629,11 +629,15 @@ describe('createStore', () => {
 
         expect(function() {
           obs.subscribe()
-        }).toThrow()
+        }).toThrowError(new TypeError('Expected the observer to be an object.'))
+
+        expect(function() {
+          obs.subscribe(null)
+        }).toThrowError(new TypeError('Expected the observer to be an object.'))
 
         expect(function() {
           obs.subscribe(() => {})
-        }).toThrow()
+        }).toThrowError(new TypeError('Expected the observer to be an object.'))
 
         expect(function() {
           obs.subscribe({})