diff --git a/test/mocks/child-process.js b/test/mocks/child-process.js
index ff86eb0b..f1281b6a 100644
--- a/test/mocks/child-process.js
+++ b/test/mocks/child-process.js
@@ -6,6 +6,7 @@ const rawCommits = [
 module.exports = {
   exec: (command, cb) => {
     if (/contains/.test(command)) {
+      if (/notinhistory/.test(command)) return cb(new Error())
       return cb(null, `whatever\nmaster\n`)
     }