diff --git a/src/MqttPlugin.cpp b/src/MqttPlugin.cpp
index 0914337..bf81f5d 100644
--- a/src/MqttPlugin.cpp
+++ b/src/MqttPlugin.cpp
@@ -98,9 +98,9 @@ void MqttPlugin::downstreamHandler(char *topic, uint8_t *payload, unsigned int l
     String topicStr = String(topic);
     int topicRootLength = topicRoot.length();
     if(topicStr.length() > topicRootLength){
-        int baseTopicLength = topicStr.substring(0, topicRootLength).length();
-        String localTopic = topicStr.substring(topicRootLength);
-        if(baseTopicLength == topicRootLength){
+        String baseTopic = topicStr.substring(0, topicRootLength);
+        if(baseTopic.compareTo(topicRoot) == 0){
+            String localTopic = topicStr.substring(topicRootLength);
             String direction = localTopic.substring(0,4);
             if(direction == "/in/" ){
                 String localSubTopic = localTopic.substring(direction.length());