diff --git a/setup.cfg b/setup.cfg
index be490b7f9c5bcd2025108b3c6c17bb4bc7973b02..9ea1ddbc4fea695ac2e0746889c32e4e510c7ce7 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -14,6 +14,7 @@ markers =
     piltest:    Requires Pillow
     noroottest: Need to be executed as non-root user (will fail otherwise)
     longtest:   Takes a long time
+    unixtest:   Only works on *nix systems
 
 
 testpaths = tests