diff --git a/core/task/state.go b/core/task/state.go
index a4c80fc6..cdf5e821 100644
--- a/core/task/state.go
+++ b/core/task/state.go
@@ -68,7 +68,7 @@ func (s State) X(other State) State {
 	if s == other {
 		return s
 	}
-	if s == ERROR {
+	if s == ERROR || other == ERROR {
 		return ERROR
 	}
 	if s != other {
diff --git a/core/task/state_test.go b/core/task/state_test.go
index 11a9f35c..c7e1cfca 100644
--- a/core/task/state_test.go
+++ b/core/task/state_test.go
@@ -49,8 +49,8 @@ var _ = Describe("task state", func() {
 				Expect(task.ERROR.X(task.RUNNING)).To(Equal(task.ERROR))
 				Expect(task.ERROR.X(task.INVARIANT)).To(Equal(task.ERROR))
 
-				Expect(task.UNKNOWN.X(task.ERROR)).To(Equal(task.ERROR)) // FIXME: this fails
-				Expect(task.RUNNING.X(task.ERROR)).To(Equal(task.ERROR)) // FIXME: this fails
+				Expect(task.UNKNOWN.X(task.ERROR)).To(Equal(task.ERROR))
+				Expect(task.RUNNING.X(task.ERROR)).To(Equal(task.ERROR))
 				Expect(task.INVARIANT.X(task.ERROR)).To(Equal(task.ERROR))
 			})
 		})