diff --git a/libs/bt/include/psemek/bt/conditional.hpp b/libs/bt/include/psemek/bt/conditional.hpp
index fa2b8b8b..3e4c5b23 100644
--- a/libs/bt/include/psemek/bt/conditional.hpp
+++ b/libs/bt/include/psemek/bt/conditional.hpp
@@ -35,24 +35,35 @@ namespace psemek::bt
 
 		status update(Time dt, Args ... args) override
 		{
-			if (condition_result_)
+			try
 			{
-				if (*condition_result_)
-					return true_branch_->update(dt, args...);
-				else
-					return false_branch_->update(dt, args...);
-			}
-			else
-			{
-				auto result = condition_->update(dt, args...);
-
-				if (auto finished = std::get_if<typename node_type::finished>(&result))
+				if (condition_result_)
 				{
-					condition_result_ = finished->result;
-					return running{};
+					if (*condition_result_)
+						return true_branch_->update(dt, args...);
+					else
+						return false_branch_->update(dt, args...);
 				}
+				else
+				{
+					auto result = condition_->update(dt, args...);
 
-				return result;
+					if (auto finished = std::get_if<typename node_type::finished>(&result))
+					{
+						condition_result_ = finished->result;
+						if (*condition_result_)
+							true_branch_->start(args...);
+						else
+							false_branch_->start(args...);
+						return running{};
+					}
+
+					return result;
+				}
+			}
+			catch (assertion_failed_exception const &)
+			{
+				return finished{false};
 			}
 		}