diff --git a/src/decoration.cpp b/src/decoration.cpp
index 6f806f8..f968de4 100644
--- a/src/decoration.cpp
+++ b/src/decoration.cpp
@@ -308,7 +308,7 @@ class wayfire_pixdecor : public wf::plugin_interface_t
         theme_methods->register_method("pixdecor/theme-configure",
             [this] (wf::json_t data, wf::ipc::client_interface_t *client)
         {
-            if (!client || !data["version"].is_int64() || data["version"].as_int64() != 1 ||
+            if (!client || !data.is_object() || !data["version"].is_int64() || data["version"].as_int64() != 1 ||
                 !data["instance"].is_string() || data["instance"].as_string() != theme_instance ||
                 (theme_owner && theme_owner != client))
                 return wf::ipc::json_error("Unavailable theme owner or instance");