diff --git a/addons/sammi/lib/sammi_api.gd b/addons/sammi/lib/sammi_api.gd
index dbd35c6..340db5c 100644
--- a/addons/sammi/lib/sammi_api.gd
+++ b/addons/sammi/lib/sammi_api.gd
@@ -74,13 +74,16 @@ func set_variable(name: String, value: Variant, button_id: String = "") -> bool:
 		last_error_description = response.error_message
 		return false
 
-func delete_variable(name: String, button_id) -> bool:
-	var api_path: String = "/api" % name
+func delete_variable(name: String, button_id: String = "") -> bool:
+	var api_path: String = "/api"
 	var req: Dictionary = {
 		"request": "deleteVariable",
-		"name": name,
-		"buttonID": button_id
+		"name": name
 	}
+	
+	if button_id != "":
+		req["buttonID"] = button_id
+	
 	client.request(SammiClient.Method.POST, api_path, JSON.stringify(req))
 	var response: SammiClient.SammiResponse = await client.request_completed
 	if response.code == 200: