diff --git a/lib/command.js b/lib/command.js
index 0b76a244..0bca97b7 100644
--- a/lib/command.js
+++ b/lib/command.js
@@ -179,8 +179,9 @@ module.exports = function (proto) {
     */
 
   proto._spawn = function _spawn (args, bufferOutput, callback) {
+    var appPath = this._options.appPath || '';
     var bin = this._options.imageMagick
-      ? args.shift()
+      ? appPath + args.shift()
       : 'gm'
 
     var proc = spawn(bin, args)