diff --git a/ts/smartnpm.classes.npmpackage.ts b/ts/smartnpm.classes.npmpackage.ts
index 4dac900..6541fae 100644
--- a/ts/smartnpm.classes.npmpackage.ts
+++ b/ts/smartnpm.classes.npmpackage.ts
@@ -122,6 +122,9 @@ export class NpmPackage {
       // lets find the best matching release
       const versionStrings = this.allVersions.map((packageVersion) => packageVersion.version);
       const bestMatchingVersion = targetVersion.getBestMatch(versionStrings);
+      if (!bestMatchingVersion) {
+        return null;
+      }
       tarballUrl = this.allVersions.find(
         (packageVersion) => packageVersion.version === bestMatchingVersion
       ).dist.tarball;
@@ -142,6 +145,7 @@ export class NpmPackage {
         console.log(err);
       },
       () => {
+        done.resolve(null);
         subscription.unsubscribe();
       }
     );