diff --git a/sw/controller/src/cfg.c b/sw/controller/src/cfg.c
index d7db3f8..29cec9e 100644
--- a/sw/controller/src/cfg.c
+++ b/sw/controller/src/cfg.c
@@ -655,6 +655,9 @@ void cfg_process (void) {
                         led_activity_on();
                         error = sd_card_init();
                         led_activity_off();
+                        if (error != SD_OK) {
+                            sd_release_lock(SD_LOCK_N64);
+                        }
                     }
                     break;
 
diff --git a/sw/controller/src/usb.c b/sw/controller/src/usb.c
index 70a1a1a..99f9a0b 100644
--- a/sw/controller/src/usb.c
+++ b/sw/controller/src/usb.c
@@ -404,6 +404,9 @@ static void usb_rx_process (void) {
                             led_activity_on();
                             error = sd_card_init();
                             led_activity_off();
+                            if (error != SD_OK) {
+                                sd_release_lock(SD_LOCK_USB);
+                            }
                         }
                         break;