diff --git a/src/livecodes/core.ts b/src/livecodes/core.ts
index 1aaa723ab..1c55ee3e0 100644
--- a/src/livecodes/core.ts
+++ b/src/livecodes/core.ts
@@ -1166,7 +1166,6 @@ const loadConfig = async (
 
   // load config
   await bootstrap(true);
-
   await applyConfig(config);
 
   changingContent = false;
@@ -3740,29 +3739,30 @@ const configureToolsPane = (
   tools: Config['tools'] | undefined,
   mode: Config['mode'] | undefined,
 ) => {
+  if (!toolsPane) return;
   if (mode === 'result' && (!tools || tools.status === '' || tools.status === 'none')) {
-    toolsPane?.hide();
+    toolsPane.hide();
     return;
   }
   if (tools?.active) {
-    toolsPane?.setActiveTool(tools.active);
+    toolsPane.setActiveTool(tools.active);
   }
   if (!tools) {
-    toolsPane?.close();
+    toolsPane.close();
     return;
   }
   if (tools.status === 'none') {
-    toolsPane?.hide();
+    toolsPane.hide();
     return;
   }
   if (tools.status === 'full') {
-    toolsPane?.maximize();
+    toolsPane.maximize();
   }
   if (tools.status === 'open') {
-    toolsPane?.open();
+    toolsPane.open();
   }
   if (tools.status === 'closed' || tools.status === '') {
-    toolsPane?.close();
+    toolsPane.close();
   }
   // TODO: handle tools.enabled
 };
diff --git a/src/livecodes/languages/ruby-wasm/lang-ruby-wasm-script.ts b/src/livecodes/languages/ruby-wasm/lang-ruby-wasm-script.ts
index 35fdcfd1d..53da421af 100644
--- a/src/livecodes/languages/ruby-wasm/lang-ruby-wasm-script.ts
+++ b/src/livecodes/languages/ruby-wasm/lang-ruby-wasm-script.ts
@@ -34,7 +34,8 @@ livecodes.rubyWasm.run =
     await init(hasImports(code));
     const { DefaultRubyVM } = (window as any)['ruby-wasm-wasi'];
     const { vm } = await DefaultRubyVM(livecodes.rubyWasm.module);
-    vm.eval(code);
+    const patch = code.includes('$0') ? '$0 = __FILE__\\n' : '';
+    vm.eval(patch + code);
     parent.postMessage({ type: 'loading', payload: false }, '*');
   });
 
diff --git a/src/livecodes/languages/ruby/lang-ruby.ts b/src/livecodes/languages/ruby/lang-ruby.ts
index b16c879ed..a91b98d8d 100644
--- a/src/livecodes/languages/ruby/lang-ruby.ts
+++ b/src/livecodes/languages/ruby/lang-ruby.ts
@@ -30,7 +30,8 @@ export const ruby: LanguageSpecs = {
           'ruby',
           config,
         );
-        return (self as any).Opal.compile(code, options);
+        const patch = code.includes('$0') ? '$0 = __FILE__\\n' : '';
+        return (self as any).Opal.compile(patch + code, options);
       };
     },
     scripts: ({ compiled, config }) => {