diff --git a/engine.build.lua b/engine.build.lua
index 37958dc..ea06e71 100644
--- a/engine.build.lua
+++ b/engine.build.lua
@@ -13,6 +13,10 @@ local settings = CopySettings(global_settings, "Engine")
 settings.cc.includes:Add("include/")
 settings.cc.includes:Add("source/")
 
+if global_settings.debug then
+	settings.cc.flags:Add("-DSPECTRE_DEBUG")
+end
+
 -- FreeType2
 settings.cc.includes:Add("vendor/FreeType2/include")