diff --git a/cef1/include/cef_request_handler.h b/cef1/include/cef_request_handler.h
index 0ee758f07..a9c7f1d66 100644
--- a/cef1/include/cef_request_handler.h
+++ b/cef1/include/cef_request_handler.h
@@ -132,7 +132,7 @@ class CefRequestHandler : public virtual CefBase {
   // CefDownloadHandler instance that will recieve the file contents. Return
   // true to download the file or false to cancel the file download.
   ///
-  /*--cef()--*/
+  /*--cef(optional_param=mimeType)--*/
   virtual bool GetDownloadHandler(CefRefPtr<CefBrowser> browser,
                                   const CefString& mimeType,
                                   const CefString& fileName,
diff --git a/cef1/libcef_dll/cpptoc/request_handler_cpptoc.cc b/cef1/libcef_dll/cpptoc/request_handler_cpptoc.cc
index 084b33ac4..b499c1b46 100644
--- a/cef1/libcef_dll/cpptoc/request_handler_cpptoc.cc
+++ b/cef1/libcef_dll/cpptoc/request_handler_cpptoc.cc
@@ -254,10 +254,6 @@ int CEF_CALLBACK request_handler_get_download_handler(
   DCHECK(browser);
   if (!browser)
     return 0;
-  // Verify param: mimeType; type: string_byref_const
-  DCHECK(mimeType);
-  if (!mimeType)
-    return 0;
   // Verify param: fileName; type: string_byref_const
   DCHECK(fileName);
   if (!fileName)
@@ -266,6 +262,7 @@ int CEF_CALLBACK request_handler_get_download_handler(
   DCHECK(handler);
   if (!handler)
     return 0;
+  // Unverified params: mimeType
 
   // Translate param: handler; type: refptr_same_byref
   CefRefPtr<CefDownloadHandler> handlerPtr;
diff --git a/cef1/libcef_dll/ctocpp/request_handler_ctocpp.cc b/cef1/libcef_dll/ctocpp/request_handler_ctocpp.cc
index 7dfd0af98..32f25d3ba 100644
--- a/cef1/libcef_dll/ctocpp/request_handler_ctocpp.cc
+++ b/cef1/libcef_dll/ctocpp/request_handler_ctocpp.cc
@@ -217,14 +217,11 @@ bool CefRequestHandlerCToCpp::GetDownloadHandler(CefRefPtr<CefBrowser> browser,
   DCHECK(browser.get());
   if (!browser.get())
     return false;
-  // Verify param: mimeType; type: string_byref_const
-  DCHECK(!mimeType.empty());
-  if (mimeType.empty())
-    return false;
   // Verify param: fileName; type: string_byref_const
   DCHECK(!fileName.empty());
   if (fileName.empty())
     return false;
+  // Unverified params: mimeType
 
   // Translate param: handler; type: refptr_same_byref
   cef_download_handler_t* handlerStruct = NULL;