diff --git a/lib/datasource/ruby-version/index.js b/lib/datasource/ruby-version/index.js
index 61a00b4839881c895f8e804aa4ddbb5d1f8edebf..69226616f1bf168993f5486e9ab4e376a1c4e173 100644
--- a/lib/datasource/ruby-version/index.js
+++ b/lib/datasource/ruby-version/index.js
@@ -39,6 +39,6 @@ async function getPkgReleases() {
       throw new Error('registry-failure');
     }
     logger.warn({ err }, 'Ruby release lookup failure: Unknown error');
-    return null;
+    throw new Error('registry-failure');
   }
 }
diff --git a/test/datasource/ruby-version.spec.js b/test/datasource/ruby-version.spec.js
index c6709d68cab602df477af8913ef88a34ed161908..da32d03f95ced95cb80320d842cd9576355d5b47 100644
--- a/test/datasource/ruby-version.spec.js
+++ b/test/datasource/ruby-version.spec.js
@@ -18,9 +18,15 @@ describe('datasource/gradle', () => {
       const res = await getPkgReleases();
       expect(res).toMatchSnapshot();
     });
-    it('returns null for empty result', async () => {
+    it('throws for empty result', async () => {
       got.mockReturnValueOnce({ body: {} });
-      expect(await getPkgReleases()).toBeNull();
+      let e;
+      try {
+        await getPkgReleases();
+      } catch (err) {
+        e = err;
+      }
+      expect(e).toBeDefined();
     });
 
     it('throws for 404', async () => {