diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index f0a8bdb..fe8e6c5 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -8,7 +8,7 @@ jobs:
     strategy:
       matrix:
         os: [macos-latest, windows-latest]
-        php-version: ['5.6', '7.0', '7.1', '7.2', '7.3', '7.4', '8.0', '8.1', '8.2', '8.3']
+        php-version: ['5.6', '7.0', '7.1', '7.2', '7.3', '7.4', '8.0', '8.1', '8.2', '8.3', '8.4']
     name: Test on ${{ matrix.os }} & PHP ${{ matrix.php-version }}
     steps:
       - name: Checkout
diff --git a/src/PHPFmt.ts b/src/PHPFmt.ts
index d10a349..02a368e 100644
--- a/src/PHPFmt.ts
+++ b/src/PHPFmt.ts
@@ -222,7 +222,7 @@ export class PHPFmt {
       } else {
         if (
           compare(phpVersion, '5.6.0', '<') ||
-          compare(phpVersion, '8.4.0, '>')
+          compare(phpVersion, '8.4.0', '>')
         ) {
           throw new PHPFmtError('PHP version < 5.6 or > 8.4');
         }