diff --git a/package.json b/package.json
index bad58a17..752c860d 100644
--- a/package.json
+++ b/package.json
@@ -36,6 +36,7 @@
     "coveralls": "^2.11.4",
     "cz-conventional-changelog": "^1.1.4",
     "mkdirp": "^0.5.1",
+    "mock-spawn": "^0.2.6",
     "nixt": "^0.5.0",
     "nock": "^8.0.0",
     "npm-registry-couchapp": "^2.6.11",
diff --git a/src/lib/commits.js b/src/lib/commits.js
index b1f74faa..86b4d5a1 100644
--- a/src/lib/commits.js
+++ b/src/lib/commits.js
@@ -1,4 +1,4 @@
-var exec = require('child_process').exec
+var childProcess = require('child_process')
 
 var log = require('npmlog')
 
@@ -13,7 +13,7 @@ module.exports = function (config, cb) {
 
   if (!from) return extract()
 
-  exec('git branch --no-color --contains ' + from, function (err, stdout) {
+  childProcess.exec('git branch --no-color --contains ' + from, function (err, stdout) {
     var inHistory = false
     var branches
 
@@ -47,28 +47,33 @@ module.exports = function (config, cb) {
   })
 
   function extract () {
-    exec(
-      'git log -E --format=%H==SPLIT==%B==END== ' + range,
-      {
-        maxBuffer: 1024 * 1024 // 1MB instead of 220KB (issue #286)
-      },
-      function (err, stdout) {
-        if (err) return cb(err)
+    var child = childProcess.spawn('git', ['log', '-E', '--format=%H==SPLIT==%B==END==', range])
+    var stdout = ''
+    var err = ''
 
-        cb(null, String(stdout).split('==END==\n')
+    child.stdout.on('data', function (data) {
+      stdout += data
+    })
 
+    child.stderr.on('data', function (data) {
+      err += data
+    })
+
+    child.on('close', function (code) {
+      if (err || code) return cb(err)
+
+      cb(null, String(stdout).split('==END==\n')
         .filter(function (raw) {
           return !!raw.trim()
         })
-
         .map(function (raw) {
           var data = raw.split('==SPLIT==')
           return {
             hash: data[0],
             message: data[1]
           }
-        }))
-      }
-    )
+        })
+      )
+    })
   }
 }
diff --git a/test/mocks/child-process.js b/test/mocks/child-process.js
index 87b68bea..15373721 100644
--- a/test/mocks/child-process.js
+++ b/test/mocks/child-process.js
@@ -1,3 +1,15 @@
+var mockSpawn = require('mock-spawn')()
+mockSpawn.setStrategy(function (command, args, opts) {
+  return function (cb) {
+    this.stdout.write(
+      /\.\.HEAD/.test(args.join(' '))
+        ? rawCommits[0]
+        : rawCommits.join()
+    )
+    cb(0)
+  }
+})
+
 const rawCommits = [
   'hash-one==SPLIT==commit-one==END==\n',
   'hash-two==SPLIT==commit-two==END==\n'
@@ -12,13 +24,7 @@ module.exports = {
       if (/notinhistory/.test(command)) return cb(new Error())
       return cb(null, 'whatever\nmaster\n')
     }
-
-    cb(
-      null,
-      /\.\.HEAD/.test(command)
-        ? rawCommits[0]
-        : rawCommits.join()
-    )
   },
+  spawn: mockSpawn,
   '@noCallThru': true
 }