Add Appveyor badge.
diff --git a/README.md b/README.md
index cc9fdfb..5730ddc 100644
--- a/README.md
+++ b/README.md
@@ -31,4 +31,5 @@
 If you want to reach the authors in private, use <libzip@nih.at>.
 
 ![Travis Build Status](https://api.travis-ci.org/nih-at/libzip.svg?branch=master)
+[![Appveyor Build status](https://ci.appveyor.com/api/projects/status/5x1raqqjro4wny7r?svg=true)](https://ci.appveyor.com/project/0-wiz-0/libzip)
 ![Coverity Status](https://scan.coverity.com/projects/127/badge.svg?flat=1)