diff --git a/fm_hci/fm_hci_api.h b/fm_hci/fm_hci_api.h
index 4c41509..1602fbb 100644
--- a/fm_hci/fm_hci_api.h
+++ b/fm_hci/fm_hci_api.h
@@ -64,7 +64,7 @@
 } fm_power_state_t;
 
 typedef int (*event_notification_cb_t)(unsigned char *buf);
-typedef int (*hci_close_done_cb_t)();
+typedef int (*hci_close_done_cb_t)(void);
 
 
 struct fm_hci_callbacks_t {
diff --git a/helium/radio_helium_hal.c b/helium/radio_helium_hal.c
index 42be704..79e69f5 100644
--- a/helium/radio_helium_hal.c
+++ b/helium/radio_helium_hal.c
@@ -1092,7 +1092,7 @@
     return 0;
 }
 
-int fm_hci_close_done()
+int fm_hci_close_done(void)
 {
     ALOGI("fm_hci_close_done");
     const fm_hal_callbacks_t *ptr = NULL;