diff --git a/zfsbk.sh b/zfsbk.sh
index 8ffe3ef..8dd4293 100755
--- a/zfsbk.sh
+++ b/zfsbk.sh
@@ -117,9 +117,8 @@ then
 fi
 
 # remove backup file if requested
-if [ "x$CLEAR_BKFILE" = x ]
+if [ "x$CLEAR_BKFILE" != x ]
 then
     rm -f $bkfile
 fi
 
-if