diff --git a/package.json b/package.json
index ffa68ef..2cb804b 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@csbnlu/jawks-private-keys-provisioner",
-  "version": "0.0.16",
+  "version": "0.0.17",
   "devDependencies": {
     "@types/aws-lambda": "^8.10.143",
     "@types/luxon": "^3.4.2",
diff --git a/src/bin/provision-private-keys.mts b/src/bin/provision-private-keys.mts
index 87a567b..41c041d 100644
--- a/src/bin/provision-private-keys.mts
+++ b/src/bin/provision-private-keys.mts
@@ -41,7 +41,12 @@ const environmentConfigSchema = z.object({
       if (value === undefined) {
         return undefined;
       }
-      return parseInt(value);
+      const parsedValue = parseInt(value);
+      if (isNaN(parsedValue)) {
+        console.error("Invalid privateKeysRefreshIntervalInDays");
+        return undefined;
+      }
+      return parsedValue;
     }),
 });