diff --git a/tests/zfs-tests/include/blkdev.shlib b/tests/zfs-tests/include/blkdev.shlib
index d87a52524e..5a750bf1b1 100644
--- a/tests/zfs-tests/include/blkdev.shlib
+++ b/tests/zfs-tests/include/blkdev.shlib
@@ -259,7 +259,7 @@ function get_device_dir #device
 {
 	typeset device=$1
 
-	if ! is_freebsd && ! $(is_physical_device $device) ; then
+	if ! is_freebsd && ! is_physical_device $device; then
 		if [[ $device != "/" ]]; then
 			device=${device%/*}
 		fi
diff --git a/tests/zfs-tests/tests/functional/cli_root/zpool_add/setup.ksh b/tests/zfs-tests/tests/functional/cli_root/zpool_add/setup.ksh
index 4b5f44a2a6..9ede9e48fb 100755
--- a/tests/zfs-tests/tests/functional/cli_root/zpool_add/setup.ksh
+++ b/tests/zfs-tests/tests/functional/cli_root/zpool_add/setup.ksh
@@ -34,7 +34,7 @@
 
 verify_runnable "global"
 
-if ! $(is_physical_device $DISKS) ; then
+if ! is_physical_device $DISKS; then
 	log_unsupported "This directory cannot be run on raw files."
 fi
 
diff --git a/tests/zfs-tests/tests/functional/cli_root/zpool_create/setup.ksh b/tests/zfs-tests/tests/functional/cli_root/zpool_create/setup.ksh
index efdafe51a0..57a08227d2 100755
--- a/tests/zfs-tests/tests/functional/cli_root/zpool_create/setup.ksh
+++ b/tests/zfs-tests/tests/functional/cli_root/zpool_create/setup.ksh
@@ -34,7 +34,7 @@
 
 verify_runnable "global"
 
-if ! $(is_physical_device $DISKS) ; then
+if ! is_physical_device $DISKS; then
 	log_unsupported "This directory cannot be run on raw files."
 fi
 
diff --git a/tests/zfs-tests/tests/functional/cli_root/zpool_destroy/zpool_destroy_001_pos.ksh b/tests/zfs-tests/tests/functional/cli_root/zpool_destroy/zpool_destroy_001_pos.ksh
index 2d9ec78211..041a1d00cb 100755
--- a/tests/zfs-tests/tests/functional/cli_root/zpool_destroy/zpool_destroy_001_pos.ksh
+++ b/tests/zfs-tests/tests/functional/cli_root/zpool_destroy/zpool_destroy_001_pos.ksh
@@ -61,7 +61,7 @@ function cleanup
 
 set -A datasets "$TESTPOOL" "$TESTPOOL2"
 
-if ! $(is_physical_device $DISKS) ; then
+if ! is_physical_device $DISKS; then
 	log_unsupported "This case cannot be run on raw files."
 fi
 
diff --git a/tests/zfs-tests/tests/functional/cli_root/zpool_export/setup.ksh b/tests/zfs-tests/tests/functional/cli_root/zpool_export/setup.ksh
index 925f3e4af8..664fb2ddd8 100755
--- a/tests/zfs-tests/tests/functional/cli_root/zpool_export/setup.ksh
+++ b/tests/zfs-tests/tests/functional/cli_root/zpool_export/setup.ksh
@@ -30,7 +30,7 @@
 
 DISK=${DISKS%% *}
 
-if ! $(is_physical_device $DISK) ; then
+if ! is_physical_device $DISK; then
 	log_unsupported "Only partitionable physical disks can be used"
 fi
 
diff --git a/tests/zfs-tests/tests/functional/cli_root/zpool_import/setup.ksh b/tests/zfs-tests/tests/functional/cli_root/zpool_import/setup.ksh
index 62c726e615..71e3b913fe 100755
--- a/tests/zfs-tests/tests/functional/cli_root/zpool_import/setup.ksh
+++ b/tests/zfs-tests/tests/functional/cli_root/zpool_import/setup.ksh
@@ -35,7 +35,7 @@
 verify_runnable "global"
 verify_disk_count "$DISKS" 2
 
-if ! $(is_physical_device $ZFS_DISK1) ; then
+if ! is_physical_device $ZFS_DISK1; then
 	log_unsupported "Only partitionable physical disks can be used"
 fi
 
diff --git a/tests/zfs-tests/tests/functional/write_dirs/setup.ksh b/tests/zfs-tests/tests/functional/write_dirs/setup.ksh
index 3f10c7f74f..156c316628 100755
--- a/tests/zfs-tests/tests/functional/write_dirs/setup.ksh
+++ b/tests/zfs-tests/tests/functional/write_dirs/setup.ksh
@@ -34,7 +34,7 @@
 
 verify_runnable "global"
 
-if ! $(is_physical_device $DISKS) ; then
+if ! is_physical_device $DISKS; then
 	log_unsupported "This directory cannot be run on raw files."
 fi
 
diff --git a/tests/zfs-tests/tests/functional/zvol/zvol_misc/zvol_misc_001_neg.ksh b/tests/zfs-tests/tests/functional/zvol/zvol_misc/zvol_misc_001_neg.ksh
index fa70044e11..25325ddda6 100755
--- a/tests/zfs-tests/tests/functional/zvol/zvol_misc/zvol_misc_001_neg.ksh
+++ b/tests/zfs-tests/tests/functional/zvol/zvol_misc/zvol_misc_001_neg.ksh
@@ -45,7 +45,7 @@
 
 verify_runnable "global"
 
-if ! $(is_physical_device $DISKS) ; then
+if ! is_physical_device $DISKS; then
 	log_unsupported "This directory cannot be run on raw files."
 fi
 
diff --git a/tests/zfs-tests/tests/functional/zvol/zvol_misc/zvol_misc_003_neg.ksh b/tests/zfs-tests/tests/functional/zvol/zvol_misc/zvol_misc_003_neg.ksh
index f473c4b4fe..2b8e509931 100755
--- a/tests/zfs-tests/tests/functional/zvol/zvol_misc/zvol_misc_003_neg.ksh
+++ b/tests/zfs-tests/tests/functional/zvol/zvol_misc/zvol_misc_003_neg.ksh
@@ -46,7 +46,7 @@
 
 verify_runnable "global"
 
-if ! $(is_physical_device $DISKS) ; then
+if ! is_physical_device $DISKS; then
 	log_unsupported "This directory cannot be run on raw files."
 fi
 
diff --git a/tests/zfs-tests/tests/functional/zvol/zvol_misc/zvol_misc_004_pos.ksh b/tests/zfs-tests/tests/functional/zvol/zvol_misc/zvol_misc_004_pos.ksh
index 6fea074edf..6978873683 100755
--- a/tests/zfs-tests/tests/functional/zvol/zvol_misc/zvol_misc_004_pos.ksh
+++ b/tests/zfs-tests/tests/functional/zvol/zvol_misc/zvol_misc_004_pos.ksh
@@ -45,7 +45,7 @@
 
 verify_runnable "global"
 
-if ! $(is_physical_device $DISKS) ; then
+if ! is_physical_device $DISKS; then
 	log_unsupported "This directory cannot be run on raw files."
 fi
 
diff --git a/tests/zfs-tests/tests/functional/zvol/zvol_misc/zvol_misc_005_neg.ksh b/tests/zfs-tests/tests/functional/zvol/zvol_misc/zvol_misc_005_neg.ksh
index 8248608e70..48dfe6d938 100755
--- a/tests/zfs-tests/tests/functional/zvol/zvol_misc/zvol_misc_005_neg.ksh
+++ b/tests/zfs-tests/tests/functional/zvol/zvol_misc/zvol_misc_005_neg.ksh
@@ -45,7 +45,7 @@
 
 verify_runnable "global"
 
-if ! $(is_physical_device $DISKS) ; then
+if ! is_physical_device $DISKS; then
 	log_unsupported "This directory cannot be run on raw files."
 fi
 
diff --git a/tests/zfs-tests/tests/functional/zvol/zvol_misc/zvol_misc_006_pos.ksh b/tests/zfs-tests/tests/functional/zvol/zvol_misc/zvol_misc_006_pos.ksh
index ad841e2a5e..08726a7c37 100755
--- a/tests/zfs-tests/tests/functional/zvol/zvol_misc/zvol_misc_006_pos.ksh
+++ b/tests/zfs-tests/tests/functional/zvol/zvol_misc/zvol_misc_006_pos.ksh
@@ -45,7 +45,7 @@
 
 verify_runnable "global"
 
-if ! $(is_physical_device $DISKS) ; then
+if ! is_physical_device $DISKS; then
 	log_unsupported "This directory cannot be run on raw files."
 fi