diff --git a/app/httpsig.py b/app/httpsig.py
index cbeab9a..0e67281 100644
--- a/app/httpsig.py
+++ b/app/httpsig.py
@@ -96,7 +96,7 @@ class HTTPXSigAuth(httpx.Auth):
             bh.update(r.content)
             bodydigest = "SHA-256=" + base64.b64encode(bh.digest()).decode("utf-8")
 
-        date = datetime.utcnow().strftime("%Y-%m-%d %H:%M:%S GMT")
+        date = datetime.utcnow().strftime("%a, %d %b %Y %H:%M:%S GMT")
         r.headers["Date"] = date
         sigheaders = {}
         if bodydigest: