diff --git a/include/ghc/filesystem.hpp b/include/ghc/filesystem.hpp
index a319def..e5ff86c 100644
--- a/include/ghc/filesystem.hpp
+++ b/include/ghc/filesystem.hpp
@@ -254,6 +254,10 @@
 #include <experimental/string_view>
 #endif
 
+#ifndef PATH_MAX
+#define PATH_MAX 4096
+#endif
+
 //- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 // Behaviour Switches (see README.md, should match the config in test/filesystem_test.cpp):
 //- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -