diff --git a/.changeset/many-eels-share.md b/.changeset/many-eels-share.md
new file mode 100644
index 00000000..7e233066
--- /dev/null
+++ b/.changeset/many-eels-share.md
@@ -0,0 +1,5 @@
+---
+'@sigstore/conformance': patch
+---
+
+Set node 18.17.x as the minimum supported version
diff --git a/package-lock.json b/package-lock.json
index 3c319206..8fbd5aa7 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -12602,7 +12602,7 @@
         "tslib": "^2.7.0"
       },
       "engines": {
-        "node": ">=18.0.0"
+        "node": "^18.17.0 || >=20.5.0"
       }
     },
     "packages/core": {
diff --git a/packages/conformance/package.json b/packages/conformance/package.json
index 9ff67677..d90eaa3a 100644
--- a/packages/conformance/package.json
+++ b/packages/conformance/package.json
@@ -33,6 +33,6 @@
     "topicSeparator": " "
   },
   "engines": {
-    "node": ">=18.0.0"
+    "node": "^18.17.0 || >=20.5.0"
   }
 }