diff --git a/libfprint/fprint.h b/libfprint/fprint.h
index 76682ed..d5bb3e5 100644
--- a/libfprint/fprint.h
+++ b/libfprint/fprint.h
@@ -342,7 +342,7 @@ void fp_set_pollfd_notifiers(fp_pollfd_added_cb added_cb,
 /* Library */
 int fp_init(void);
 void fp_exit(void);
-void fp_set_debug(int level);
+void fp_set_debug(int level) LIBFPRINT_DEPRECATED;
 
 /* Asynchronous I/O */