diff --git a/src/ExitAirTempSensor.cpp b/src/ExitAirTempSensor.cpp
index 61a03fb..e256bb1 100644
--- a/src/ExitAirTempSensor.cpp
+++ b/src/ExitAirTempSensor.cpp
@@ -595,7 +595,7 @@
         }
         for (const auto& item : subtree)
         {
-            size_t lastSlash = item.first.rfind("/");
+            size_t lastSlash = item.first.rfind('/');
             if (lastSlash == std::string::npos ||
                 lastSlash == item.first.size() || item.second.empty())
             {