diff --git a/core/server/middleware/static-theme.js b/core/server/middleware/static-theme.js
index 3b6654f8c7..bfa3a06959 100644
--- a/core/server/middleware/static-theme.js
+++ b/core/server/middleware/static-theme.js
@@ -11,10 +11,14 @@ function isBlackListedFileType(file) {
 }
 
 function forwardToExpressStatic(req, res, next) {
-    express.static(
-        path.join(config.paths.themePath, req.app.get('activeTheme')),
-        {maxAge: utils.ONE_YEAR_MS}
-    )(req, res, next);
+    if (!req.app.get('activeTheme')) {
+        next();
+    } else {
+        express.static(
+            path.join(config.paths.themePath, req.app.get('activeTheme')),
+            {maxAge: utils.ONE_YEAR_MS}
+        )(req, res, next);
+    }
 }
 
 function staticTheme() {
diff --git a/core/test/unit/middleware/static-theme_spec.js b/core/test/unit/middleware/static-theme_spec.js
index 6a19d3df64..52b2a00733 100644
--- a/core/test/unit/middleware/static-theme_spec.js
+++ b/core/test/unit/middleware/static-theme_spec.js
@@ -65,4 +65,24 @@ describe('staticTheme', function () {
             done();
         });
     });
+
+    it('should not error if active theme is missing', function (done) {
+        var req = {
+                url: 'myvalidfile.css',
+                app: {
+                    get: function () { return undefined; }
+                }
+            },
+            activeThemeStub,
+            sandbox = sinon.sandbox.create();
+
+        activeThemeStub = sandbox.spy(req.app, 'get');
+
+        staticTheme(null)(req, null, function (reqArg, res, next2) {
+            /*jshint unused:false */
+            sandbox.restore();
+            next.called.should.be.false;
+            done();
+        });
+    });
 });