diff --git a/src/proto.h b/src/proto.h
index 686a3d6..78f814c 100644
--- a/src/proto.h
+++ b/src/proto.h
@@ -90,6 +90,7 @@
 # include "fileio.pro"
 # include "filepath.pro"
 # include "findfile.pro"
+# include "float.pro"
 # include "fold.pro"
 # include "getchar.pro"
 # include "gui_xim.pro"