diff --git a/httpbin/core.py b/httpbin/core.py
index ca0b904..7d8464e 100644
--- a/httpbin/core.py
+++ b/httpbin/core.py
@@ -58,8 +58,8 @@ def set_cors_headers(response):
         # http://www.w3.org/TR/cors/#access-control-allow-methods-response-header
         response.headers['Access-Control-Allow-Methods'] = 'GET, POST, PUT, DELETE, PATCH, OPTIONS'
         response.headers['Access-Control-Max-Age'] = '3600'  # 1 hour cache
-        if request.headers.get('Access-Control-Request-Headers', None) != None:
-            response.headers['Access-Control-Allow-Headers'] = request.headers.get('Access-Control-Request-Headers', "")
+        if request.headers.get('Access-Control-Request-Headers') is not None:
+            response.headers['Access-Control-Allow-Headers'] = request.headers.get('Access-Control-Request-Headers')
     return response