diff --git a/.github/workflows/build-and-test.yml b/.github/workflows/build-and-test.yml
index df766c6..88cfe12 100644
--- a/.github/workflows/build-and-test.yml
+++ b/.github/workflows/build-and-test.yml
@@ -13,7 +13,7 @@ jobs:
       matrix:
         os: [ ubuntu , macos ]
         hhvm:
-          - 4.59
+          - 4.66
           - latest
           - nightly
     runs-on: ${{matrix.os}}-latest
diff --git a/composer.json b/composer.json
index 27987cc..c75505c 100644
--- a/composer.json
+++ b/composer.json
@@ -13,7 +13,7 @@
     "hhvm/hhvm-autoload": "^2.0|^3.0"
   },
   "require": {
-    "hhvm": "^4.59",
+    "hhvm": "^4.66",
     "hhvm/hsl": "^4.15"
   },
   "provide": {