diff --git a/fhem/FHEM/92_FileLog.pm b/fhem/FHEM/92_FileLog.pm
index ae06d6486..cf379f67d 100755
--- a/fhem/FHEM/92_FileLog.pm
+++ b/fhem/FHEM/92_FileLog.pm
@@ -97,7 +97,7 @@ FileLog_Log($$)
 
       print $fh "$t $n $s\n";
       $fh->flush;
-      $fh->sync;
+      $fh->sync if !($^O eq 'MSWin32'); #not implemented in Windows
     }
   }
   return "";