diff --git a/compat/mingw.c b/compat/mingw.c
index 628a3941d2..869be1a1fd 100644
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -3117,6 +3117,9 @@ static void setup_windows_environment(void)
 			setenv("HOME", tmp, 1);
 	}
 
+	if (!getenv("LC_ALL") && !getenv("LC_CTYPE") && !getenv("LANG"))
+		setenv("LC_CTYPE", "C.UTF-8", 1);
+
 	/*
 	 * Change 'core.symlinks' default to false, unless native symlinks are
 	 * enabled in MSys2 (via 'MSYS=winsymlinks:nativestrict'). Thus we can