diff --git a/artifacts/scripting/headers/define_extra.h b/artifacts/scripting/headers/define_extra.h
index 9934983e..f3295abb 100644
--- a/artifacts/scripting/headers/define_extra.h
+++ b/artifacts/scripting/headers/define_extra.h
@@ -109,6 +109,7 @@
 #define PROTO_IT_SIZE       (112)
 #define PROTO_IT_WEIGHT     (116)
 #define PROTO_IT_COST       (120)
+#define PROTO_IT_INV_FID    (124)
 
 // weapons
 #define PROTO_WP_ANIM        (36)
diff --git a/sfall/FalloutEngine/Functions_def.h b/sfall/FalloutEngine/Functions_def.h
index 417ed83c..5ff7b8aa 100644
--- a/sfall/FalloutEngine/Functions_def.h
+++ b/sfall/FalloutEngine/Functions_def.h
@@ -36,6 +36,7 @@ WRAP_WATCOM_FUNC0(void, intface_toggle_item_state)
 WRAP_WATCOM_FUNC0(void, intface_use_item)
 WRAP_WATCOM_FUNC1(long, item_w_max_ammo, GameObject*, item)
 WRAP_WATCOM_FUNC1(long, item_w_curr_ammo, GameObject*, item)
+WRAP_WATCOM_FUNC1(long, item_weight, GameObject*, item)
 // returns light level at given tile
 WRAP_WATCOM_FUNC2(long, light_get_tile, long, elevation, long, tileNum)
 WRAP_WATCOM_FUNC2(void, mouse_get_position, long*, outX, long*, outY)
diff --git a/sfall/Modules/Scripting/Handlers/Metarule.cpp b/sfall/Modules/Scripting/Handlers/Metarule.cpp
index 4be7ef29..698236e6 100644
--- a/sfall/Modules/Scripting/Handlers/Metarule.cpp
+++ b/sfall/Modules/Scripting/Handlers/Metarule.cpp
@@ -123,6 +123,7 @@ static const SfallMetarule metaruleArray[] = {
 	{"intface_show", sf_intface_show, 0, 0},
 	{"intface_hide", sf_intface_hide, 0, 0},
 	{"intface_is_hidden", sf_intface_is_hidden, 0, 0},
+	{"item_weight", sf_item_weight, 1, 1, {ARG_OBJECT}},
 	{"exec_map_update_scripts", sf_exec_map_update_scripts, 0, 0},
 	{"set_outline", sf_set_outline, 2, 2, {ARG_OBJECT, ARG_INT}},
 	{"get_outline", sf_get_outline, 1, 1, {ARG_OBJECT}},
@@ -169,6 +170,8 @@ void HandleMetarule(OpcodeContext& ctx) {
 			ctx.setArgShift(1);
 			if (ValidateMetaruleArguments(ctx, currentMetarule)) {
 				currentMetarule->func(ctx);
+			} else if (ctx.hasReturn()) {
+				ctx.setReturn(-1);
 			}
 		} else {
 			ctx.printOpcodeError("sfall_funcX(name, ...) - name '%s' is unknown.", name);
diff --git a/sfall/Modules/Scripting/Handlers/Objects.cpp b/sfall/Modules/Scripting/Handlers/Objects.cpp
index 6b3caed5..a9558d40 100644
--- a/sfall/Modules/Scripting/Handlers/Objects.cpp
+++ b/sfall/Modules/Scripting/Handlers/Objects.cpp
@@ -423,5 +423,9 @@ void sf_outlined_object(OpcodeContext& ctx) {
 	ctx.setReturn(fo::var::outlined_object);
 }
 
+void sf_item_weight(OpcodeContext& ctx) {
+	ctx.setReturn(fo::func::item_weight(ctx.arg(0).asObject()));
+}
+
 }
 }
diff --git a/sfall/Modules/Scripting/Handlers/Objects.h b/sfall/Modules/Scripting/Handlers/Objects.h
index ec1b7d9c..098cf384 100644
--- a/sfall/Modules/Scripting/Handlers/Objects.h
+++ b/sfall/Modules/Scripting/Handlers/Objects.h
@@ -77,5 +77,7 @@ void sf_get_flags(OpcodeContext&);
 
 void sf_outlined_object(OpcodeContext&);
 
+void sf_item_weight(OpcodeContext&);
+
 }
 }