diff --git a/to-edn.nix b/to-edn.nix
index d13e430..0fa5fcb 100644
--- a/to-edn.nix
+++ b/to-edn.nix
@@ -18,7 +18,7 @@ let
           "[ ${join-str (map toEDN ds)} ]"
         else
           (if isAttrs ds then
-            "{ ${join-str (mapAttrs (k: v: ":${k} ${toEDN v}") ds)} }"
+            "{ ${join-str (mapAttrsToList (k: v: ":${k} ${toEDN v}") ds)} }"
           else
             throw "unsupported type: ${builtins.typeOf ds}: ${ds}")));