diff --git a/sources/Commands/ACommandUserData.uc b/sources/Commands/ACommandUserData.uc
index 5e7ed99..8674d5f 100644
--- a/sources/Commands/ACommandUserData.uc
+++ b/sources/Commands/ACommandUserData.uc
@@ -37,7 +37,7 @@ protected function BuildData(CommandDataBuilder builder)
     builder.SubCommand(P("write"))
         .ParamText(P("groupName"))
         .ParamText(P("dataName"))
-        .ParamObject(P("newData"))
+        .ParamJSON(P("newData"))
         .Describe(P("Stores new user data {$TextEmphasis `newData`} for"
             @ "targeted user under group {$TextEmphasis `groupName`} and name"
             @ "{$TextEmphasis `dataName`}."));