diff --git a/tests/zfs-tests/include/libtest.shlib b/tests/zfs-tests/include/libtest.shlib
index 1c467ca65..407101826 100644
--- a/tests/zfs-tests/include/libtest.shlib
+++ b/tests/zfs-tests/include/libtest.shlib
@@ -3460,18 +3460,7 @@ function tunable_exists
 #
 function md5digest
 {
-	typeset file=$1
-
-	case "$UNAME" in
-	FreeBSD)
-		md5 -q $file
-		;;
-	*)
-		typeset sum _
-		read -r sum _ < <(md5sum -b $file)
-		echo $sum
-		;;
-	esac
+	openssl md5 -r $1 | awk '{print $1}'
 }
 
 #
@@ -3492,18 +3481,7 @@ function cmp_md5s {
 #
 function sha256digest
 {
-	typeset file=$1
-
-	case "$UNAME" in
-	FreeBSD)
-		sha256 -q $file
-		;;
-	*)
-		typeset sum _
-		read -r sum _ < <(sha256sum -b $file)
-		echo $sum
-		;;
-	esac
+	openssl sha256 -r $1 | awk '{print $1}'
 }
 
 function new_fs #<args>
diff --git a/tests/zfs-tests/tests/functional/cli_root/zdb/zdb_backup.ksh b/tests/zfs-tests/tests/functional/cli_root/zdb/zdb_backup.ksh
index d98ab86ab..b591b209a 100755
--- a/tests/zfs-tests/tests/functional/cli_root/zdb/zdb_backup.ksh
+++ b/tests/zfs-tests/tests/functional/cli_root/zdb/zdb_backup.ksh
@@ -47,8 +47,8 @@ sync_pool $TESTPOOL
 log_must eval "zfs send -ecL $snap > $tmpfile.1"
 log_must eval "zdb -B $TESTPOOL/$objsetid ecL > $tmpfile.2"
 
-typeset sum1=$(cat $tmpfile.1 | md5sum)
-typeset sum2=$(cat $tmpfile.2 | md5sum)
+typeset sum1=$(md5digest $tmpfile.1)
+typeset sum2=$(md5digest $tmpfile.2)
 
 log_must test "$sum1" = "$sum2"
 
diff --git a/tests/zfs-tests/tests/functional/fault/suspend_resume_single.ksh b/tests/zfs-tests/tests/functional/fault/suspend_resume_single.ksh
index 05f3ac708..6998df78a 100755
--- a/tests/zfs-tests/tests/functional/fault/suspend_resume_single.ksh
+++ b/tests/zfs-tests/tests/functional/fault/suspend_resume_single.ksh
@@ -43,7 +43,7 @@ log_assert "ensure single-disk pool resumes properly after suspend and clear"
 
 # create a file, and take a checksum, so we can compare later
 log_must dd if=/dev/urandom of=$DATAFILE bs=128K count=1
-typeset sum1=$(cat $DATAFILE | md5sum)
+typeset sum1=$(md5digest $DATAFILE)
 
 # make a debug device that we can "unplug"
 load_scsi_debug 100 1 1 1 '512b'
@@ -94,7 +94,7 @@ log_must zpool export $TESTPOOL
 log_must zpool import $TESTPOOL
 
 # sum the file we wrote earlier
-typeset sum2=$(cat /$TESTPOOL/file | md5sum)
+typeset sum2=$(md5digest /$TESTPOOL/file)
 
 # make sure the checksums match
 log_must test "$sum1" = "$sum2"