diff --git a/scripts/imgtool/image.py b/scripts/imgtool/image.py
index 5fec3c1b7..4be9be7e8 100644
--- a/scripts/imgtool/image.py
+++ b/scripts/imgtool/image.py
@@ -183,6 +183,7 @@ def tlv_sha_to_sha(tlv):
     keys.ECDSA384P1         : ['384'],
     keys.ECDSA384P1Public   : ['384'],
     keys.ECDSA256P1         : ['256'],
+    keys.ECDSA256P1Public   : ['256'],
     keys.RSA                : ['256'],
     keys.RSAPublic          : ['256'],
     # This two are set to 256 for compatibility, the right would be 512