diff --git a/include/gb.h b/include/gb.h
index 4c70d00..cd4eb8c 100644
--- a/include/gb.h
+++ b/include/gb.h
@@ -21,7 +21,9 @@ typedef struct gb_timers_t {
 } GBTimers;
 
 GBTimers *gb_timers_open(RIO *io);
-void gb_timers_open(RIO *io, GBTimers);
+void gb_timers_close(RIO *io, GBTimers *timers);
 void gb_timers_update(GBTimers *timers, ut32 cycles);
 
+extern RIOPlugin r_io_plugin_gb_timers;
+
 #endif
diff --git a/io/timers.c b/io/timers.c
index c68503a..2b80f9f 100644
--- a/io/timers.c
+++ b/io/timers.c
@@ -51,9 +51,9 @@ static bool __close(RIODesc *desc) {
 static int __write(RIO *io, RIODesc *desc, const ut8 *buf, int len) {
 	GBTimers *timers = (GBTimers *)desc->data;
 	if (timers->seek == 4) {
-		return NULL;
+		return 0;
 	}
-	int wlen = R_MIN (len, 4 - timers->seek)
+	int wlen = R_MIN (len, 4 - timers->seek);
 	ut64 endseek = timers->seek + wlen;
 	ut32 i;
 	for (i = 0; timers->seek < endseek; timers->seek++) {