diff --git a/common/os_calls.c b/common/os_calls.c
index bbec959f..d98d4027 100644
--- a/common/os_calls.c
+++ b/common/os_calls.c
@@ -1917,6 +1917,17 @@ g_signal_pipe(void (*func)(int))
 #endif
 }
 
+/*****************************************************************************/
+/* does not work in win32 */
+void APP_CC
+g_signal_usr1(void (*func)(int))
+{
+#if defined(_WIN32)
+#else
+  signal(SIGUSR1, func);
+#endif
+}
+
 /*****************************************************************************/
 /* does not work in win32 */
 int APP_CC
diff --git a/common/os_calls.h b/common/os_calls.h
index e5625d16..94b857df 100644
--- a/common/os_calls.h
+++ b/common/os_calls.h
@@ -218,6 +218,8 @@ void APP_CC
 g_signal_terminate(void (*func)(int));
 void APP_CC
 g_signal_pipe(void (*func)(int));
+void APP_CC
+g_signal_usr1(void (*func)(int));
 int APP_CC
 g_fork(void);
 int APP_CC