diff --git a/bin/tests/system/dns64/tests.sh b/bin/tests/system/dns64/tests.sh
index cb37ddae36..86ab4a4463 100644
--- a/bin/tests/system/dns64/tests.sh
+++ b/bin/tests/system/dns64/tests.sh
@@ -1278,7 +1278,7 @@ status=`expr $status + $ret`
 echo_i "checking reverse mapping ($n)"
 ret=0
 $DIG $DIGOPTS -x 2001:aaaa::10.0.0.1 @10.53.0.2 > dig.out.ns2.test$n || ret=1
-tr -d '\r' < dig.out.ns2$n | grep -i "CNAME.1.0.0.10.IN-ADDR.ARPA.$" > /dev/null || ret=1
+tr -d '\r' < dig.out.ns2.test$n | grep -i "CNAME.1.0.0.10.IN-ADDR.ARPA.$" > /dev/null || ret=1
 n=`expr $n + 1`
 if [ $ret != 0 ]; then echo_i "failed"; fi
 status=`expr $status + $ret`
diff --git a/bin/tests/system/rndc/tests.sh b/bin/tests/system/rndc/tests.sh
index ed98b1a587..909ff77814 100644
--- a/bin/tests/system/rndc/tests.sh
+++ b/bin/tests/system/rndc/tests.sh
@@ -229,7 +229,7 @@ do
 done
 serial=`awk '$3 == "serial" {print $1}' ns2/other.db`
 newserial=`expr $serial + 1`
-sed s/$serial/$newserial/ ns2/other.db > ns2/other.db.new
+sed "s/$serial/$newserial/" ns2/other.db > ns2/other.db.new
 echo 'frozen TXT "frozen addition"' >> ns2/other.db.new
 mv -f ns2/other.db.new ns2/other.db
 $RNDCCMD 10.53.0.2 thaw 2>&1 | sed 's/^/ns2 /' | cat_i
@@ -272,7 +272,7 @@ do
 done
 serial=`awk '$3 == "serial" {print $1}' ns2/nil.db`
 newserial=`expr $serial + 1`
-sed s/$serial/$newserial/ ns2/nil.db > ns2/nil.db.new
+sed "s/$serial/$newserial/" ns2/nil.db > ns2/nil.db.new
 echo 'frozen TXT "frozen addition"' >> ns2/nil.db.new
 mv -f ns2/nil.db.new ns2/nil.db
 $RNDCCMD 10.53.0.2 thaw 2>&1 | sed 's/^/ns2 /' | cat_i