diff --git a/src/reverseproxy.js b/src/reverseproxy.js
index 84e3fe13a..52912fb04 100644
--- a/src/reverseproxy.js
+++ b/src/reverseproxy.js
@@ -286,6 +286,13 @@ async function setupTlsAddon(app) {
     assert.strictEqual(typeof app, 'object');
 
     const certificateDir = `${paths.PLATFORM_DATA_DIR}/tls/${app.id}`;
+
+    // clean up any certs of old locations
+    const filenames = safe.fs.readdirSync(certificateDir) || [];
+    for (const filename of filenames) {
+        safe.fs.unlinkSync(path.join(certificateDir, filename));
+    }
+
     for (const location of getAppLocationsSync(app)) {
         const certificate = await getCertificate(location);
         writeFileSync(`${certificateDir}/${location.fqdn}.cert`, certificate.cert);