diff --git a/package.json b/package.json
index 332462c..4e7a009 100644
--- a/package.json
+++ b/package.json
@@ -35,9 +35,9 @@
     "@types/js-yaml": "^3.11.2",
     "@types/prettier": "^1.13.2",
     "del": "^3.0.0",
-    "fp-ts": "^1.10.0",
+    "fp-ts": "~1.10.0",
     "fs-extra": "^7.0.0",
-    "io-ts": "^1.2.1",
+    "io-ts": "~1.2.1",
     "io-ts-types": "^0.4.0",
     "js-yaml": "^3.12.0",
     "prettier": "^1.15.3",