diff --git a/composer.json b/composer.json
index 6367a13..69d5332 100644
--- a/composer.json
+++ b/composer.json
@@ -3,9 +3,9 @@
   "description": "Unit test helpers for Facebook projects",
   "license": "MIT",
   "require": {
-    "hhvm": "^3.28|^4.0",
+    "hhvm": "^4.0",
     "hhvm/hacktest": "^1.0",
-    "hhvm/hsl": "^3.26|^4.0",
+    "hhvm/hsl": "^4.0",
     "facebook/difflib": "^1.0.0"
   },
   "require-dev": {
diff --git a/composer.lock b/composer.lock
index e4fdd2a..be995ba 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "5ffa51748645fa1d036ff1f8233c57fe",
+    "content-hash": "a643b2edb9bf4064ff9576471565d917",
     "packages": [
         {
             "name": "facebook/difflib",
@@ -331,7 +331,7 @@
     "prefer-stable": false,
     "prefer-lowest": false,
     "platform": {
-        "hhvm": "^3.28|^4.0"
+        "hhvm": "^4.0"
     },
     "platform-dev": []
 }