diff --git a/src/cache-distributions/poetry-cache.ts b/src/cache-distributions/poetry-cache.ts
index c31fb05d4..2dcf761a1 100644
--- a/src/cache-distributions/poetry-cache.ts
+++ b/src/cache-distributions/poetry-cache.ts
@@ -48,7 +48,7 @@ class PoetryCache extends CacheDistributor {
     const hash = await glob.hashFiles(this.patterns);
     // "v2" is here to invalidate old caches of this cache distributor, which were created broken:
     const primaryKey = `${this.CACHE_KEY_PREFIX}-${process.env['RUNNER_OS']}-python-${this.pythonVersion}-${this.packageManager}-v2-${hash}`;
-    const restoreKey = undefined;
+    const restoreKey = `${this.CACHE_KEY_PREFIX}-${process.env['RUNNER_OS']}-python-${this.pythonVersion}-${this.packageManager}-`;
     return {
       primaryKey,
       restoreKey