diff --git a/src/quest_editor/QuestRunner.ts b/src/quest_editor/QuestRunner.ts
index 7930373e..6d55d39a 100644
--- a/src/quest_editor/QuestRunner.ts
+++ b/src/quest_editor/QuestRunner.ts
@@ -276,11 +276,7 @@ export class QuestRunner {
         }
 
         return {
-            bb_map_designate: (
-                area_id: number,
-                map_number: number,
-                area_variant_id: number,
-            ): void => {
+            map_designate: (area_id: number, area_variant_id: number): void => {
                 this._game_state.area_variants.set(
                     area_id,
                     this.area_store.get_variant(this._game_state.episode, area_id, area_variant_id),
diff --git a/src/quest_editor/scripting/vm/VirtualMachine.ts b/src/quest_editor/scripting/vm/VirtualMachine.ts
index 3a543619..25ca6ed0 100644
--- a/src/quest_editor/scripting/vm/VirtualMachine.ts
+++ b/src/quest_editor/scripting/vm/VirtualMachine.ts
@@ -51,6 +51,8 @@ import {
     OP_LETI,
     OP_LETW,
     OP_LIST,
+    OP_MAP_DESIGNATE,
+    OP_MAP_DESIGNATE_EX,
     OP_MOD,
     OP_MODI,
     OP_MUL,
@@ -477,7 +479,7 @@ export class VirtualMachine {
         let advance = true;
 
         const arg_vals = inst.args.map(arg => arg.value);
-        const [arg0, arg1, arg2, arg3] = arg_vals;
+        const [arg0, arg1, arg2] = arg_vals;
 
         // previous instruction must've been `list`.
         // list may not exist after the instruction
@@ -814,6 +816,18 @@ export class VirtualMachine {
             case OP_THREAD_STG.code:
                 this.start_thread(arg0);
                 break;
+            case OP_MAP_DESIGNATE.code:
+                this.io.map_designate(
+                    this.get_register_signed(arg0),
+                    this.get_register_signed(arg0 + 2),
+                );
+                break;
+            case OP_MAP_DESIGNATE_EX.code:
+                this.io.map_designate(
+                    this.get_register_signed(arg0),
+                    this.get_register_signed(arg0 + 3),
+                );
+                break;
             case OP_GET_RANDOM.code:
                 {
                     const low = this.get_register_signed(arg0);
@@ -860,7 +874,7 @@ export class VirtualMachine {
 
                 break;
             case OP_BB_MAP_DESIGNATE.code:
-                this.io.bb_map_designate(arg0, arg1, arg2, arg3);
+                this.io.map_designate(arg0, arg2);
                 break;
             default:
                 if (!this.unsupported_opcodes_logged.has(inst.opcode.code)) {
diff --git a/src/quest_editor/scripting/vm/io.ts b/src/quest_editor/scripting/vm/io.ts
index d7bd039d..5faa4493 100644
--- a/src/quest_editor/scripting/vm/io.ts
+++ b/src/quest_editor/scripting/vm/io.ts
@@ -16,12 +16,7 @@ export interface VirtualMachineInput {
  * The virtual machine calls these methods when it outputs something.
  */
 export interface VirtualMachineOutput {
-    bb_map_designate(
-        area_id: number,
-        map_number: number,
-        area_variant_id: number,
-        unknown: number,
-    ): void;
+    map_designate(area_id: number, area_variant_id: number): void;
     set_floor_handler(area_id: number, label: number): void;
     window_msg(msg: string): void;
     message(msg: string): void;
@@ -53,7 +48,7 @@ export interface VirtualMachineIO
         VirtualMachineMetaIO {}
 
 export class DefaultVirtualMachineIO implements VirtualMachineIO {
-    bb_map_designate(area_id: number, area_variant_id: number): void {
+    map_designate(area_id: number, area_variant_id: number): void {
         logger.warn(`bb_map_designate(${area_id}, ${area_variant_id})`);
     }