diff --git a/tasks/build-jsr.ts b/tasks/build-jsr.ts
index 98b178d9..387d31d0 100644
--- a/tasks/build-jsr.ts
+++ b/tasks/build-jsr.ts
@@ -1,9 +1,14 @@
 import jsonDeno from "../deno.json" with { type: "json" };
 
+let [version] = Deno.args;
+if (!version) {
+  throw new Error("a version argument is required to build the npm package");
+}
+
 await Deno.writeTextFile(
   new URL("../deno.json", import.meta.url),
   JSON.stringify({
     ...jsonDeno,
-    version: Deno.env.get("VERSION"),
+    version,
   }),
 );