diff --git a/lib/internal/util/debuglog.js b/lib/internal/util/debuglog.js
index b1f82b957b162a..17b3980d423bc0 100644
--- a/lib/internal/util/debuglog.js
+++ b/lib/internal/util/debuglog.js
@@ -1,11 +1,10 @@
 'use strict';
 
 const {
-  FunctionPrototypeBind,
   ObjectCreate,
   ObjectDefineProperty,
   RegExp,
-  RegExpPrototypeTest,
+  RegExpPrototypeExec,
   SafeArrayIterator,
   StringPrototypeToLowerCase,
   StringPrototypeToUpperCase,
@@ -17,20 +16,19 @@ const { inspect, format, formatWithOptions } = require('internal/util/inspect');
 // debuglog() before initializeDebugEnv() is called will throw.
 let debugImpls;
 
-let debugEnvRegex = /^$/;
-let testEnabled;
+let testEnabled = () => false;
 
 // `debugEnv` is initial value of process.env.NODE_DEBUG
 function initializeDebugEnv(debugEnv) {
   debugImpls = ObjectCreate(null);
   if (debugEnv) {
+    // This is run before any user code, it's OK not to use primordials.
     debugEnv = debugEnv.replace(/[|\\{}()[\]^$+?.]/g, '\\$&')
-      .replace(/\*/g, '.*')
-      .replace(/,/g, '$|^')
-      .toUpperCase();
-    debugEnvRegex = new RegExp(`^${debugEnv}$`, 'i');
+      .replaceAll('*', '.*')
+      .replaceAll(',', '$|^');
+    const debugEnvRegex = new RegExp(`^${debugEnv}$`, 'i');
+    testEnabled = (str) => RegExpPrototypeExec(debugEnvRegex, str) !== null;
   }
-  testEnabled = FunctionPrototypeBind(RegExpPrototypeTest, null, debugEnvRegex);
 }
 
 // Emits warning when user sets