diff --git a/testsuite/hostid/hostid-works b/testsuite/hostid/hostid-works
index bcfd717af..8c20bdfcc 100644
--- a/testsuite/hostid/hostid-works
+++ b/testsuite/hostid/hostid-works
@@ -1,8 +1,6 @@
 h=x$(busybox hostid)
 # Is $h a sequence of hex numbers?
-x="${h//[0123456789abcdef]/x}"
-x="${x//xxx/x}"
-x="${x//xxx/x}"
-x="${x//xxx/x}"
-x="${x//xx/x}"
-test x"$x" = x"x"
+case "$h" in
+ x*[!0-9a-f]*) false;;
+ *) true;;
+esac
diff --git a/testsuite/md5sum.tests b/testsuite/md5sum.tests
index 1068b083f..6c75b6d1c 100755
--- a/testsuite/md5sum.tests
+++ b/testsuite/md5sum.tests
@@ -30,13 +30,13 @@ result=`(
 n=0
 while test $n -le 999; do
 	echo "$text" | head -c $n | "$sum"
-	: $((n++))
+	n=$(($n+1))
 done | "$sum"
 )`
 
 if test x"$result" = x"$expected  -"; then
-    echo "PASS: $sum"
-    exit 0
+	echo "PASS: $sum"
+	exit 0
 fi
 
 echo "FAIL: $sum (r:$result exp:$expected)"
diff --git a/testsuite/testing.sh b/testsuite/testing.sh
index e7e64e58b..f5b756947 100644
--- a/testsuite/testing.sh
+++ b/testsuite/testing.sh
@@ -56,10 +56,10 @@ optional()
 {
 	SKIP=
 	while test "$1"; do
-		if test x"${OPTIONFLAGS/*:$1:*/y}" != x"y"; then
-			SKIP=1
-			return
-		fi
+		case "${OPTIONFLAGS}" in
+			*:$1:*) ;;
+			*) SKIP=1; return ;;
+		esac
 		shift
 	done
 }
diff --git a/testsuite/which/which-uses-default-path b/testsuite/which/which-uses-default-path
index 63ceb9f8f..349583dcc 100644
--- a/testsuite/which/which-uses-default-path
+++ b/testsuite/which/which-uses-default-path
@@ -1,4 +1,4 @@
-BUSYBOX=$(type -p busybox)
+BUSYBOX=$(command -pv busybox)
 SAVED_PATH=$PATH
 unset PATH
 $BUSYBOX which ls