diff --git a/index.js b/index.js
index 292d24f..0bd2a95 100644
--- a/index.js
+++ b/index.js
@@ -6,7 +6,6 @@ var isWin32 = require('os').platform() === 'win32';
 
 var slash = '/';
 var backslash = /\\/g;
-var globby = /(^|[^\\])([{[]|\([^)]+$)/;
 var escaped = /\\([!*?|[\](){}])/g;
 
 /**
@@ -33,7 +32,7 @@ module.exports = function globParent(str, opts) {
   // remove path parts that are globby
   do {
     str = pathPosixDirname(str);
-  } while (isGlob(str) || globby.test(str));
+  } while (isGlobby(str));
 
   // remove escape chars and return result
   return str.replace(escaped, '$1');
@@ -61,3 +60,16 @@ function isEnclosure(str) {
 
   return str.slice(foundIndex + 1, -1).includes(slash);
 }
+
+function isGlobby(str) {
+  if (/\([^()]+$/.test(str))  {
+    return true;
+  }
+  if (str[0] === '{' || str[0] === '[') {
+    return true;
+  }
+  if (/[^\\][{[]/.test(str)) {
+    return true;
+  }
+  return isGlob(str);
+}
diff --git a/package.json b/package.json
index 801d046..afc902a 100644
--- a/package.json
+++ b/package.json
@@ -23,7 +23,7 @@
     "test": "nyc mocha --async-only"
   },
   "dependencies": {
-    "is-glob": "^4.0.1"
+    "is-glob": "^4.0.3"
   },
   "devDependencies": {
     "eslint": "^7.0.0",
diff --git a/test/index.test.js b/test/index.test.js
index 7f1ee15..5889412 100644
--- a/test/index.test.js
+++ b/test/index.test.js
@@ -242,6 +242,12 @@ describe('glob2base test patterns', function () {
     gp('('.repeat(500000));
     done();
   });
+
+  it("should finish in reasonable time for '/('.repeat(n) + ')'", function (done) {
+    this.timeout(1000);
+    gp('/('.repeat(500000) + ')');
+    done();
+  });
 });
 
 if (isWin32) {