diff --git a/contrib/ruby/ext/trilogy-ruby/cext.c b/contrib/ruby/ext/trilogy-ruby/cext.c
index a7b8a592..eb1f46ef 100644
--- a/contrib/ruby/ext/trilogy-ruby/cext.c
+++ b/contrib/ruby/ext/trilogy-ruby/cext.c
@@ -316,6 +316,7 @@ static int _cb_ruby_wait(trilogy_sock_t *sock, trilogy_wait_t wait)
         RB_OBJ_WRITE(ctx->self, &ctx->io, rb_io_fdopen(trilogy_sock_fd(sock), O_RDWR, NULL));
     }
 
+    if (timeout) fprintf(stderr, "_cb_ruby_wait timeout: %ld.%06ld\n", timeout->tv_sec, timeout->tv_usec);
     VALUE result = rb_io_wait(ctx->io, RB_INT2NUM(wait_flag), rb_fiber_scheduler_make_timeout(timeout));
 
     if (result == RUBY_Qfalse) {