diff --git a/pkgs/development/python-modules/amazon-ion/default.nix b/pkgs/development/python-modules/amazon-ion/default.nix
index b6b93d63efbf..939c554d339d 100644
--- a/pkgs/development/python-modules/amazon-ion/default.nix
+++ b/pkgs/development/python-modules/amazon-ion/default.nix
@@ -1,5 +1,6 @@
 { lib
 , buildPythonPackage
+, cbor2
 , docopt
 , fetchFromGitHub
 , jsonconversion
@@ -41,6 +42,7 @@ buildPythonPackage rec {
   ];
 
   nativeCheckInputs = [
+    cbor2
     docopt
     pytestCheckHook
     tabulate