diff --git a/src/HwmonTempSensor.cpp b/src/HwmonTempSensor.cpp
index 52ad8fe..d4ed57f 100644
--- a/src/HwmonTempSensor.cpp
+++ b/src/HwmonTempSensor.cpp
@@ -133,7 +133,7 @@
     responseStream.clear();
     inputDev.close();
     int fd = open(path.c_str(), O_RDONLY);
-    if (fd <= 0)
+    if (fd < 0)
     {
         return; // we're no longer valid
     }