diff --git a/src/pcsc.hxx b/src/pcsc.hxx
index 6434c6e..0ec8190 100644
--- a/src/pcsc.hxx
+++ b/src/pcsc.hxx
@@ -536,7 +536,11 @@ namespace pcsc {
 
       //! @c false if last operation was not successful
       operator bool() const {
+#ifdef WIN32        
         return (_state>>30&3)==0;
+#else
+        return _state==SCARD_S_SUCCESS;
+#endif
       }
 
       //! Get the describing text of the last error