diff --git a/scripts/imgtool.nix b/scripts/imgtool.nix
index 9ac41bc..ea9ba8b 100644
--- a/scripts/imgtool.nix
+++ b/scripts/imgtool.nix
@@ -20,7 +20,7 @@
       python37.pkgs.cryptography
       python37.pkgs.intelhex
       python37.pkgs.setuptools
-      python37.pkgs.cbor
+      python37.pkgs.cbor2
     ]
   );
 in