diff --git a/README.md b/README.md
index 8028e82a..d137630c 100644
--- a/README.md
+++ b/README.md
@@ -1205,7 +1205,7 @@ Reveal.initialize({
 
 	// Don't forget to add the dependencies
 	dependencies: [
-		{ src: '//cdn.socket.io/socket.io-1.3.5.js', async: true },
+		{ src: '//cdnjs.cloudflare.com/ajax/libs/socket.io/2.2.0/socket.io.js', async: true },
 		{ src: 'plugin/multiplex/master.js', async: true },
 
 		// and if you want speaker notes
@@ -1235,7 +1235,7 @@ Reveal.initialize({
 
 	// Don't forget to add the dependencies
 	dependencies: [
-		{ src: '//cdn.socket.io/socket.io-1.3.5.js', async: true },
+		{ src: '//cdnjs.cloudflare.com/ajax/libs/socket.io/2.2.0/socket.io.js', async: true },
 		{ src: 'plugin/multiplex/client.js', async: true }
 
 		// other dependencies...
@@ -1277,7 +1277,7 @@ Reveal.initialize({
 
 	// Don't forget to add the dependencies
 	dependencies: [
-		{ src: '//cdn.socket.io/socket.io-1.3.5.js', async: true },
+		{ src: '//cdnjs.cloudflare.com/ajax/libs/socket.io/2.2.0/socket.io.js', async: true },
 		{ src: 'plugin/multiplex/client.js', async: true }
 
 		// other dependencies...
@@ -1301,7 +1301,7 @@ Reveal.initialize({
 
 	// Don't forget to add the dependencies
 	dependencies: [
-		{ src: '//cdn.socket.io/socket.io-1.3.5.js', async: true },
+		{ src: '//cdnjs.cloudflare.com/ajax/libs/socket.io/2.2.0/socket.io.js', async: true },
 		{ src: 'plugin/multiplex/master.js', async: true },
 		{ src: 'plugin/multiplex/client.js', async: true }
 
diff --git a/package.json b/package.json
index cb8a711b..35fcc513 100644
--- a/package.json
+++ b/package.json
@@ -37,7 +37,7 @@
     "grunt-retire": "^1.0.7",
     "grunt-zip": "~0.17.1",
     "mustache": "^2.3.0",
-    "socket.io": "^1.7.3"
+    "socket.io": "^2.2.0"
   },
   "license": "MIT"
 }