diff --git a/client/space_lua/runtime.ts b/client/space_lua/runtime.ts
index dff9adb7..df9f45b3 100644
--- a/client/space_lua/runtime.ts
+++ b/client/space_lua/runtime.ts
@@ -340,14 +340,22 @@ export class LuaTable implements ILuaSettable, ILuaGettable {
       return value.then(() => this.rawSet(key, value));
     }
     if (typeof key === "string") {
-      this.stringKeys[key] = value;
+      if (value === null || value === undefined) {
+        delete this.stringKeys[key];
+      } else {
+        this.stringKeys[key] = value;
+      }
     } else if (Number.isInteger(key) && key >= 1) {
       this.arrayPart[key - 1] = value;
     } else {
       if (!this.otherKeys) {
         this.otherKeys = new Map();
       }
-      this.otherKeys.set(key, value);
+      if (value === null || value === undefined) {
+        this.otherKeys.delete(key);
+      } else {
+        this.otherKeys.set(key, value);
+      }
     }
   }
 
diff --git a/client/space_lua/stdlib/table.ts b/client/space_lua/stdlib/table.ts
index 107496cc..d4bcf56b 100644
--- a/client/space_lua/stdlib/table.ts
+++ b/client/space_lua/stdlib/table.ts
@@ -1,6 +1,7 @@
 import {
   type ILuaFunction,
   LuaBuiltinFunction,
+  luaCall,
   type LuaEnv,
   luaEquals,
   luaGet,
@@ -175,7 +176,7 @@ export const tableApi = new LuaTable({
       const startIndex = fromIndex < 1 ? 1 : fromIndex;
       for (let i = startIndex; i <= tbl.length; i++) {
         const val = await luaGet(tbl, i, sf);
-        if (await criteriaFn.call(sf, val)) {
+        if (await luaCall(criteriaFn, [val], sf.astCtx!, sf)) {
           return new LuaMultiRes([i, val]);
         }
       }
diff --git a/client/space_lua/stdlib/table_test.lua b/client/space_lua/stdlib/table_test.lua
index a7d55eda..7b5e680a 100644
--- a/client/space_lua/stdlib/table_test.lua
+++ b/client/space_lua/stdlib/table_test.lua
@@ -126,6 +126,13 @@ assert(table.includes(t, "three"))
 assert(table.includes(t, true))
 assert(not table.includes(t, "missing"))
 
+-- Test using table as set
+local s = {}
+s["something"] = true
+assertEqual(#table.keys(s), 1)
+-- Remove from the map
+s["something"] = nil
+assertEqual(#table.keys(s), 0)
 
 -- Error cases
 local success, error = pcall(function()
@@ -147,4 +154,4 @@ local t = { 0, 1, 2, 3 }
 local idx, two = table.find(t, function(v) return v == 2 end)
 assertEqual(idx, 3)
 assertEqual(two, 2)
-assertEqual(table.find(t, function(v) return v == 4 end), nil)
\ No newline at end of file
+assertEqual(table.find(t, function(v) return v == 4 end), nil)