diff --git a/build/ensure-sizzle.js b/build/ensure-sizzle.js
new file mode 100644
index 000000000..01a128efb
--- /dev/null
+++ b/build/ensure-sizzle.js
@@ -0,0 +1,40 @@
+var fs = require( "fs" ),
+	bower = require( "grunt-bowercopy/node_modules/bower" ),
+	sizzleLoc = __dirname + "/../src/sizzle/dist/sizzle.js",
+	rversion = /Engine v(\d+\.\d+\.\d+(?:-\w+)?)/;
+
+/**
+ * Retrieve the latest tag of Sizzle from bower
+ * @param {Function(string)} callback
+ */
+function getLatestSizzle( callback ) {
+	bower.commands.info( "sizzle", "version" )
+		.on( "end", callback );
+}
+
+/**
+ * Ensure the /src folder has the latest tag of Sizzle
+ * @param {Object} Release
+ * @param {Function} callback
+ */
+function ensureSizzle( Release, callback ) {
+	console.log();
+	console.log( "Checking Sizzle version..." );
+	getLatestSizzle(function( latest ) {
+		var match = rversion.exec( fs.readFileSync( sizzleLoc, "utf8" ) ),
+			version = match ? match[ 1 ] : "Not Found";
+
+		if ( version !== latest ) {
+			console.log(
+				"The Sizzle version in the src folder (" + version.red +
+				") is not the latest tag (" + latest.green + ")."
+			);
+			Release.confirm( callback );
+		} else {
+			console.log( "Sizzle is latest (" + latest.green + ")" );
+			callback();
+		}
+	});
+}
+
+module.exports = ensureSizzle;
diff --git a/build/release.js b/build/release.js
index 529137da7..9f6b2e2a9 100644
--- a/build/release.js
+++ b/build/release.js
@@ -3,6 +3,7 @@ module.exports = function( Release ) {
 	var
 		fs = require( "fs" ),
 		shell = require( "shelljs" ),
+		ensureSizzle = require( "./ensure-sizzle" ),
 
 		devFile = "dist/jquery.js",
 		minFile = "dist/jquery.min.js",
@@ -116,6 +117,13 @@ module.exports = function( Release ) {
 		npmPublish: true,
 		issueTracker: "trac",
 		contributorReportId: 508,
+		/**
+		 * Ensure the repo is in a proper state before release
+		 * @param {Function} callback
+		 */
+		checkRepoState: function( callback ) {
+			ensureSizzle( Release, callback );
+		},
 		/**
 		 * Generates any release artifacts that should be included in the release.
 		 * The callback must be invoked with an array of files that should be
diff --git a/package.json b/package.json
index d9953d485..ebf559f60 100644
--- a/package.json
+++ b/package.json
@@ -30,6 +30,7 @@
   ],
   "dependencies": {},
   "devDependencies": {
+    "colors": "^0.6.2",
     "commitplease": "1.7.0",
     "grunt": "0.4.2",
     "grunt-bowercopy": "0.7.1",