diff --git a/cxx/filesystem.h b/cxx/filesystem.h
index 0462ee6..e1f152b 100644
--- a/cxx/filesystem.h
+++ b/cxx/filesystem.h
@@ -198,7 +198,8 @@ namespace filesystem {
 		}
 		path& remove_filename();
 		path& replace_filename(const path& replacement);
-		path& replace_extension(const path& replacement = path());
+		path& replace_extension(/* const path& replacement = path() */);
+		path& replace_extension(const path& replacement);
 
 		void  swap(path& rhs) noexcept {
 			std::swap(_path, rhs._path);
diff --git a/mpw-shell.cpp b/mpw-shell.cpp
index 7410ce6..68e38e6 100644
--- a/mpw-shell.cpp
+++ b/mpw-shell.cpp
@@ -9,6 +9,7 @@
 #include <stdlib.h>
 #include <cerrno>
 #include <signal.h>
+#include <sys/waitpid.h>
 
 #include "mpw-shell.h"
 #include "fdset.h"