diff --git a/libs/evoral/src/libsmf/smf.c b/libs/evoral/src/libsmf/smf.c
index 227ea8c263..8b8f1bb604 100644
--- a/libs/evoral/src/libsmf/smf.c
+++ b/libs/evoral/src/libsmf/smf.c
@@ -237,7 +237,7 @@ smf_event_new(void)
  * \return Event containing MIDI data or NULL.
  */
 smf_event_t *
-smf_event_new_from_pointer(void *midi_data, size_t len)
+smf_event_new_from_pointer(const void *midi_data, size_t len)
 {
 	smf_event_t *event;
 
diff --git a/libs/evoral/src/libsmf/smf.h b/libs/evoral/src/libsmf/smf.h
index 8ead92f598..8311254841 100644
--- a/libs/evoral/src/libsmf/smf.h
+++ b/libs/evoral/src/libsmf/smf.h
@@ -371,7 +371,7 @@ void smf_event_remove_from_track(smf_event_t *event);
 
 /* Routines for manipulating smf_event_t. */
 smf_event_t *smf_event_new(void) WARN_UNUSED_RESULT;
-smf_event_t *smf_event_new_from_pointer(void *midi_data, size_t len) WARN_UNUSED_RESULT;
+smf_event_t *smf_event_new_from_pointer(const void *midi_data, size_t len) WARN_UNUSED_RESULT;
 smf_event_t *smf_event_new_from_bytes(int byte1, int byte2, int byte3) WARN_UNUSED_RESULT;
 smf_event_t *smf_event_new_textual(int type, const char *text);
 void         smf_event_delete(smf_event_t *event);