diff --git a/sway/config/output.c b/sway/config/output.c
index 88514ac0d..aa4cf9460 100644
--- a/sway/config/output.c
+++ b/sway/config/output.c
@@ -27,8 +27,10 @@ int output_name_cmp(const void *item, const void *data) {
 void output_get_identifier(char *identifier, size_t len,
 		struct sway_output *output) {
 	struct wlr_output *wlr_output = output->wlr_output;
-	snprintf(identifier, len, "%s %s %s", wlr_output->make, wlr_output->model,
-		wlr_output->serial);
+	snprintf(identifier, len, "%s %s %s",
+		wlr_output->make ? wlr_output->make : "Unknown",
+		wlr_output->model ? wlr_output->model : "Unknown",
+		wlr_output->serial ? wlr_output->serial : "Unknown");
 }
 
 const char *sway_output_scale_filter_to_string(enum scale_filter_mode scale_filter) {
diff --git a/sway/ipc-json.c b/sway/ipc-json.c
index 06121d627..e682bc362 100644
--- a/sway/ipc-json.c
+++ b/sway/ipc-json.c
@@ -248,11 +248,11 @@ static void ipc_json_describe_output(struct sway_output *output,
 
 	json_object_object_add(object, "primary", json_object_new_boolean(false));
 	json_object_object_add(object, "make",
-			json_object_new_string(wlr_output->make));
+			json_object_new_string(wlr_output->make ? wlr_output->make : "Unknown"));
 	json_object_object_add(object, "model",
-			json_object_new_string(wlr_output->model));
+			json_object_new_string(wlr_output->model ? wlr_output->model : "Unknown"));
 	json_object_object_add(object, "serial",
-			json_object_new_string(wlr_output->serial));
+			json_object_new_string(wlr_output->serial ? wlr_output->serial : "Unknown"));
 
 	json_object *modes_array = json_object_new_array();
 	struct wlr_output_mode *mode;