diff --git a/samples/http-image-cloudevents/requirements.txt b/samples/http-image-cloudevents/requirements.txt
index 10f7286..197e001 100644
--- a/samples/http-image-cloudevents/requirements.txt
+++ b/samples/http-image-cloudevents/requirements.txt
@@ -2,3 +2,4 @@ flask
 requests
 Pillow
 pytest
+cloudevents
diff --git a/samples/http-json-cloudevents/requirements.txt b/samples/http-json-cloudevents/requirements.txt
index 71bd969..1f69ece 100644
--- a/samples/http-json-cloudevents/requirements.txt
+++ b/samples/http-json-cloudevents/requirements.txt
@@ -1,3 +1,4 @@
 flask
 requests
 pytest
+cloudevents