diff --git a/Eask b/Eask
index be260e2..349f13a 100644
--- a/Eask
+++ b/Eask
@@ -9,7 +9,8 @@
 
 (script "test" "echo \"Error: no test specified\" && exit 1")
 
-(source "melpa")
+(source 'gnu)
+(source 'melpa)
 
 (depends-on "emacs" "24.1")
 
@@ -17,3 +18,7 @@
  (depends-on "ert-runner"))
 
 (setq network-security-level 'low)  ; see https://github.com/jcs090218/setup-emacs-windows/issues/156#issuecomment-932956432
+
+(add-hook 'eask-before-compile-hook
+           (lambda (&rest _)
+             (setq byte-compile-error-on-warn t)))