diff --git a/lib/tesseract.js b/lib/tesseract.js
index 74a252a..2f7e13c 100644
--- a/lib/tesseract.js
+++ b/lib/tesseract.js
@@ -46,7 +46,8 @@ var Tesseract = {
       options = null;
     }
 
-    options = utils.merge(Tesseract.options, options);
+    var defaultOptions = utils.merge({}, Tesseract.options);
+    options = utils.merge(defaultOptions, options);
 
     // generate output file name
     var output = path.resolve(tmpdir, 'node-tesseract-' + uuid.v4());