diff --git a/tests/playTests.sh b/tests/playTests.sh
index 09a7377f2..985b12d2d 100755
--- a/tests/playTests.sh
+++ b/tests/playTests.sh
@@ -408,7 +408,7 @@ $ECHO "\n===>  cover dictionary builder : advanced options "
 TESTFILE=../programs/zstdcli.c
 ./datagen > tmpDict
 $ECHO "- Create first dictionary"
-$ZSTD --train-cover=k=46,d=8 *.c ../programs/*.c -o tmpDict
+$ZSTD --train-cover=k=46,d=8,split=80 *.c ../programs/*.c -o tmpDict
 cp $TESTFILE tmp
 $ZSTD -f tmp -D tmpDict
 $ZSTD -d tmp.zst -D tmpDict -fo result
@@ -422,6 +422,9 @@ cmp tmpDict tmpDict1 && die "dictionaries should have different ID !"
 $ECHO "- Create dictionary with size limit"
 $ZSTD --train-cover=steps=8 *.c ../programs/*.c -o tmpDict2 --maxdict=4K
 rm tmp*
+$ECHO "- Compare size of dictionary from 90% training samples with 80% training samples"
+$ZSTD --train-cover=split=90 -r *.c ../programs/*.c
+$ZSTD --train-cover=split=80 -r *.c ../programs/*.c
 
 $ECHO "\n===>  legacy dictionary builder "