diff --git a/.appveyor.yml b/.appveyor.yml
index 877112084..d81d7a5fa 100644
--- a/.appveyor.yml
+++ b/.appveyor.yml
@@ -20,6 +20,7 @@ build_script:
   - setupFMILibrary.bat
   - setupFmi4c.bat
   - setupXerces.bat
+  - setupZlib.bat
   - setupLibzip.bat
   - setupDCPLib.bat
 #  - setupHDF5.bat (takes to long to build)