diff --git a/compat/mingw.c b/compat/mingw.c
index dcdb3e5bc9..4713369cd1 100644
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -2930,6 +2930,9 @@ static void setup_windows_environment(void)
 	 */
 	if (!(tmp = getenv("MSYS")) || !strstr(tmp, "winsymlinks:nativestrict"))
 		has_symlinks = 0;
+
+	if (!getenv("LC_ALL") && !getenv("LC_CTYPE") && !getenv("LANG"))
+		setenv("LC_CTYPE", "C", 1);
 }
 
 int handle_long_path(wchar_t *path, int len, int max_path, int expand)