diff --git a/Foundation/CPURLRequest.j b/Foundation/CPURLRequest.j
index 5d6b7fc9b..b18b9bd81 100644
--- a/Foundation/CPURLRequest.j
+++ b/Foundation/CPURLRequest.j
@@ -68,7 +68,7 @@
         _HTTPMethod = @"GET";
         _HTTPHeaderFields = [CPDictionary dictionary];
         
-        [self setValue:"Thu, 1 Jan 1970 00:00:00 GMT" forHTTPHeaderField:"If-Modified-Since"];
+        [self setValue:"Thu, 01 Jan 1970 00:00:00 GMT" forHTTPHeaderField:"If-Modified-Since"];
         [self setValue:"no-cache" forHTTPHeaderField:"Cache-Control"];
         [self setValue:"XMLHttpRequest" forHTTPHeaderField:"X-Requested-With"];
     }