diff --git a/extensions/meson.build b/extensions/meson.build
index 1a526eb309..60bc0ef88f 100644
--- a/extensions/meson.build
+++ b/extensions/meson.build
@@ -1,6 +1,6 @@
 subdir('goat-exercises')
 
-if not meson.is_cross_build() and lua.found() and (platform_windows or not relocatable_bundle)
+if not meson.is_cross_build() and is_variable('lua') and lua.found() and (platform_windows or not relocatable_bundle)
   lua_config = configuration_data()
   # For Windows, we set the binary name only.
   # For other OSes, we use the full path (when not in a relocatable