diff --git a/composer.json b/composer.json
index aa89141..891f44a 100644
--- a/composer.json
+++ b/composer.json
@@ -21,7 +21,7 @@
   ],
   "require": {
     "php": ">=8.3",
-    "milpa/core": "^0.6.2 || ^0.7 || ^0.8",
+    "milpa/core": ">=0.6.2 <1.0",
     "psr/http-message": "^2.0",
     "psr/http-server-handler": "^1.0",
     "psr/http-server-middleware": "^1.0"