diff --git a/Images/px4esc-v1.prototype b/Images/px4esc-v1.prototype
index 7c15b97af2..aee968cdc9 100644
--- a/Images/px4esc-v1.prototype
+++ b/Images/px4esc-v1.prototype
@@ -7,6 +7,7 @@
     "summary": "PX4ESCv1",
     "version": "0.1",
     "image_size": 0,
+    "image_maxsize": 475136,
     "git_identity": "",
     "board_revision": 0
 }