diff --git a/src/PSUSensor.cpp b/src/PSUSensor.cpp
index a7156a7..7c9e109 100644
--- a/src/PSUSensor.cpp
+++ b/src/PSUSensor.cpp
@@ -128,7 +128,7 @@
     responseStream.clear();
     inputDev.close();
     int fd = open(path.c_str(), O_RDONLY);
-    if (fd <= 0)
+    if (fd < 0)
     {
         return;
     }