diff --git a/repoproxy.py b/repoproxy.py
index e1d76d2..765598b 100644
--- a/repoproxy.py
+++ b/repoproxy.py
@@ -142,8 +142,8 @@ class RepoProxy:
         login, password = base64.b64decode(credentials).decode('utf8').split(':')
       except Exception:
         return self.unauthorized()
-    elif 'HTTP_X_SSL_CLIENT_CERT' in request.env:
-      sslcert = str(urllib.parse.unquote(request.env['HTTP_X_SSL_CLIENT_CERT']))
+    elif 'EARTHWORM_SSL_CLIENT_CERT' in request.env:
+      sslcert = str(urllib.parse.unquote(request.env['EARTHWORM_SSL_CLIENT_CERT']))
 
     url = None
     with db.holder.Holder(request.server.dbpool, readonly = True) as connection: