diff --git a/lib/url.c b/lib/url.c
index a78a2412f..38b9552f7 100644
--- a/lib/url.c
+++ b/lib/url.c
@@ -577,6 +577,10 @@ CURLcode Curl_init_userdefined(struct UserDefined *set)
   result = setstropt(&set->str[STRING_SSL_CAFILE_ORIG], CURL_CA_BUNDLE);
   if(result)
     return result;
+
+  result = setstropt(&set->str[STRING_SSL_CAFILE_PROXY], CURL_CA_BUNDLE);
+  if(result)
+    return result;
 #endif
 #if defined(CURL_CA_PATH)
   result = setstropt(&set->str[STRING_SSL_CAPATH_ORIG], CURL_CA_PATH);