diff --git a/wGRR b/wGRR
index d61bfbf0532b1ae00851aec7fde41a4a55af2ee2..0d790bbf309723272f8938fbadc0b39c12e61c42 100755
--- a/wGRR
+++ b/wGRR
@@ -325,7 +325,7 @@ fi
 duration=$SECONDS
 printf "%-10s  --  %s\n" "[INFO]" "Sorting results"
 printf "%-10s  --  %s\n" "[TIME]" $(textifyDuration $duration)
-sort -u -m "$tmp"/$OUT.wgrr_part.* | $AWKEXE 'BEGIN{print "GenomeA\tGenomeB\twGRR1\tCommon1\tRealLengthA\tRealLengthB\twGRR2\tCommon2\tEffectiveLength1A\tEffectiveLength1B\twGRR3\tCommon3\tEffectiveLength2A\tEffectiveLength2B"}1' > $OUT.wgrr.txt
+sort -m "$tmp"/$OUT.wgrr_part.* | sort -u -k1,1V -k2,2V | $AWKEXE 'BEGIN{print "GenomeA\tGenomeB\twGRR1\tCommon1\tRealLengthA\tRealLengthB\twGRR2\tCommon2\tEffectiveLength1A\tEffectiveLength1B\twGRR3\tCommon3\tEffectiveLength2A\tEffectiveLength2B"}1' > $OUT.wgrr.txt
 
 if [[ ! -f "$OUT".wgrr.txt ]] ; then
 	echo "[ERROR]     --  Failed to sort the wGRR table."