2 files changed, 2 insertions, 2 deletions

diff --git a/minui/events.cpp b/minui/events.cpp
index a6b9671ed..e6e7bd28c 100644
--- a/minui/events.cpp
+++ b/minui/events.cpp
@@ -204,7 +204,7 @@ int ev_sync_key_state(ev_set_key_callback set_key_cb, void* data) {
     return 0;
 }
 
-void ev_iterate_available_keys(std::function<void(int)> f) {
+void ev_iterate_available_keys(const std::function<void(int)>& f) {
     // Use unsigned long to match ioctl's parameter type.
     unsigned long ev_bits[BITS_TO_LONGS(EV_MAX)]; // NOLINT
     unsigned long key_bits[BITS_TO_LONGS(KEY_MAX)]; // NOLINT
diff --git a/minui/minui.h b/minui/minui.h
index e3bc00548..b2648fb33 100644
--- a/minui/minui.h
+++ b/minui/minui.h
@@ -67,7 +67,7 @@ typedef int (*ev_set_key_callback)(int code, int value, void* data);
 int ev_init(ev_callback input_cb, void* data);
 void ev_exit();
 int ev_add_fd(int fd, ev_callback cb, void* data);
-void ev_iterate_available_keys(std::function<void(int)> f);
+void ev_iterate_available_keys(const std::function<void(int)>& f);
 int ev_sync_key_state(ev_set_key_callback set_key_cb, void* data);
 
 // 'timeout' has the same semantics as poll(2).