diff --git a/lib/internal/process.js b/lib/internal/process.js
index 3de3ae1603deb5..d6a4b6c4fcd97e 100644
--- a/lib/internal/process.js
+++ b/lib/internal/process.js
@@ -128,11 +128,22 @@ function setupConfig(_source) {
   // strip the gyp comment line at the beginning
   config = config.split('\n')
       .slice(1)
-      .join('\n')
-      .replace(/"/g, '\\"')
-      .replace(/'/g, '"');
+      .join('\n');
+
+  // convert the Python syntax to proper JSON
+  // We cannot use a regex due to side effects on static properties of RegExp
+  // (e.g., RegExp.$_).
+  let out = '';
+  for (const ch of config) {
+    if (ch === '"')
+      out += '\\"';
+    else if (ch === "'")
+      out += '"';
+    else
+      out += ch;
+  }
 
-  process.config = JSON.parse(config, function(key, value) {
+  process.config = JSON.parse(out, function(key, value) {
     if (value === 'true') return true;
     if (value === 'false') return false;
     return value;
diff --git a/test/parallel/test-regress-GH-node-18930.js b/test/parallel/test-regress-GH-node-18930.js
new file mode 100644
index 00000000000000..3e246490b0624b
--- /dev/null
+++ b/test/parallel/test-regress-GH-node-18930.js
@@ -0,0 +1,8 @@
+/* eslint-disable node-core/required-modules */
+// The ordinarily required common module has side effects on RegExp.
+'use strict';
+
+const assert = require('assert');
+
+for (const prop of "&'+123456789_`".split('').map((c) => `$${c}`))
+  assert.strictEqual(RegExp[prop], '');