diff --git a/src/proto/os_unix.pro b/src/proto/os_unix.pro
index ee22b4a..7dd8e23 100644
--- a/src/proto/os_unix.pro
+++ b/src/proto/os_unix.pro
@@ -85,4 +85,5 @@
 int xsmp_handle_requests(void);
 void xsmp_init(void);
 void xsmp_close(void);
+int gpm_available(void);
 /* vim: set ft=c : */