diff --git a/src/Core.gd b/src/Core.gd
index 7a9bf3f..6da7776 100644
--- a/src/Core.gd
+++ b/src/Core.gd
@@ -175,6 +175,8 @@ func register_custom_module(module_name: String, module_class: CoreBaseModule) -
 		logger.errorf("Core", "Registering module failed: A custom module with the name \"" + module_name + "\" already exists.")
 		return false
 	module_class.name = module_name
+	logger.diagf("Core", "Updating variables")
+	module_class.core = self
 	logger.diagf("Core", "Adding module to SceneTree")
 	custom_modules_node.add_child(module_class)
 	logger.diagf("Core", "Merging module with custom_modules")
@@ -201,7 +203,7 @@ func get_custom_module(module_name: String) -> CoreBaseModule:
 	logger.diagf("Core", "Getting custom module \"" + module_name + "\"")
 	if !custom_modules.has(module_name):
 		logger.errorf("Core", "Getting module failed: A custom module with the name \"" + module_name + "\" does not exist.")
-		return
+		return null
 	return custom_modules[module_name]
 
 # (Re-)Load configuration