diff --git a/ext/io/event/selector/uring.c b/ext/io/event/selector/uring.c
index 58b78ae..1523808 100644
--- a/ext/io/event/selector/uring.c
+++ b/ext/io/event/selector/uring.c
@@ -710,6 +710,7 @@ VALUE IO_Event_Selector_URing_io_read(VALUE self, VALUE fiber, VALUE io, VALUE b
 	size_t maximum_size = size - offset;
 	while (maximum_size) {
 		int result = io_read(selector, fiber, descriptor, (char*)base+offset, maximum_size);
+		fprintf(stderr, "io_read: %d, %s\n", result, IO_Event_try_again(-result) ? "try again" : "failed");
 		
 		if (result > 0) {
 			total += result;