diff --git a/tests/checkout/icase.c b/tests/checkout/icase.c
index 3a6ce2078..211738070 100644
--- a/tests/checkout/icase.c
+++ b/tests/checkout/icase.c
@@ -4,7 +4,7 @@
 #include "path.h"
 
 #ifdef GIT_WIN32
-# include <Windows.h>
+# include <windows.h>
 #endif
 
 static git_repository *repo;