diff --git a/Rsconscript b/Rsconscript
index 8c3f2de..172b92b 100644
--- a/Rsconscript
+++ b/Rsconscript
@@ -6,10 +6,11 @@ end
 
 build do
   main_env = Rscons::Environment.new do |env|
-    env["LIBS"] += %w[X11 GLX]
     env["sources"] = glob("src/**/*.{c,d}")
+    env["CCFLAGS"] += %w[-Wall]
     env["D_IMPORT_PATH"] += glob("src/**")
     env["DFLAGS"] += %w[-Wall]
+    env["LIBS"] += %w[X11 GLX]
     env.Program("jes", "${sources}")
   end
   main_env.clone do |env|