diff --git a/bc.lua b/bc.lua
index ef5c4f8fea7d..306cb119cd00 100644
--- a/bc.lua
+++ b/bc.lua
@@ -171,7 +171,7 @@ function BaseControl:finalize(waits, timeout)
       if timeout ~= nil then
         timeout_remaining = timeout - (computer.uptime() - tstart)
         if timeout_remaining <= 0 then
-          break
+          error("timeout")
         end
       end
       -- Wait until the next register arrives
diff --git a/tests/timeout.lua b/tests/timeout.lua
index 6fcd245466f1..d5167391ee3b 100644
--- a/tests/timeout.lua
+++ b/tests/timeout.lua
@@ -50,5 +50,7 @@ end
 function test_timeout_finalize()
   local bc1 = BaseControl:new()
   local addr1 = network.get_scene()
-  bc1:finalize({"to_final1"}, 0.1)
+  assert_error_match("timeout", function()
+    bc1:finalize({"to_final1"}, 0.1)
+  end)
 end