diff --git a/docs/source/luascript/ref-core.rst b/docs/source/luascript/ref-core.rst
index 0b3760255aab4..29234691592e0 100644
--- a/docs/source/luascript/ref-core.rst
+++ b/docs/source/luascript/ref-core.rst
@@ -197,6 +197,8 @@ machine:popmessage([msg])
 machine:logerror(msg)
     Writes the message to the machine error log.  This may be displayed in a
     debugger window, written to a file, or written to the standard error output.
+machine:side_effects_disabled()
+    Returns a Boolean indicating whether side effects are disabled.
 
 Properties
 ~~~~~~~~~~
@@ -253,8 +255,6 @@ machine.exit_pending (read-only)
     A Boolean indicating whether the emulation session is scheduled to exit.
 machine.hard_reset_pending (read-only)
     A Boolean indicating whether a hard reset of the emulated system is pending.
-machine.side_effects_disabled (read-only)
-    A Boolean indicating whether side effects are disabled.
 machine.devices (read-only)
     A :ref:`device enumerator <luascript-ref-devenum>` that yields all
     :ref:`devices <luascript-ref-device>` in the emulated system.
diff --git a/src/frontend/mame/luaengine.cpp b/src/frontend/mame/luaengine.cpp
index 41b94e353e8f2..b8cd3d829635e 100644
--- a/src/frontend/mame/luaengine.cpp
+++ b/src/frontend/mame/luaengine.cpp
@@ -1446,6 +1446,7 @@ void lua_engine::initialize()
 					m.popmessage();
 			});
 	machine_type.set_function("logerror", [] (running_machine &m, char const *str) { m.logerror("[luaengine] %s\n", str); });
+	machine_type.set_function("side_effects_disabled", &running_machine::side_effects_disabled);
 	machine_type["time"] = sol::property(&running_machine::time);
 	machine_type["system"] = sol::property(&running_machine::system);
 	machine_type["parameters"] = sol::property(&running_machine::parameters);
@@ -1491,7 +1492,6 @@ void lua_engine::initialize()
 				}
 				return nullptr;
 			});
-	machine_type["side_effects_disabled"] = sol::property(&running_machine::side_effects_disabled);
 
 
 	auto game_driver_type = sol().registry().new_usertype<game_driver>("game_driver", sol::no_constructor);