diff --git a/bitbake/lib/bb/ui/knotty.py b/bitbake/lib/bb/ui/knotty.py
index 2693a78..ed978e2 100644
--- a/bitbake/lib/bb/ui/knotty.py
+++ b/bitbake/lib/bb/ui/knotty.py
@@ -203,6 +203,7 @@ def main(server, eventHandler):
                 break
             if isinstance(event, bb.command.CommandFailed):
                 return_value = event.exitcode
+                errors = errors + 1
                 logger.error("Command execution failed: %s", event.error)
                 break
             if isinstance(event, bb.command.CommandExit):