diff --git a/lib/config/decrypt.js b/lib/config/decrypt.js
index 489c63a3b642a38425a2de2e582f80c721950321..c3c9f5667e22ce65bf145df0ce7d0a9290ab522b 100644
--- a/lib/config/decrypt.js
+++ b/lib/config/decrypt.js
@@ -35,6 +35,7 @@ function decryptConfig(config, privateKey) {
                 .toString();
               // let it throw if the above fails
             }
+            // istanbul ignore if
             if (!decryptedStr.length) {
               throw new Error('empty string');
             }