diff --git a/dev-tools/reformat-shell.sh b/dev-tools/reformat-shell.sh
index dbbdaa9..d76eae7 100755
--- a/dev-tools/reformat-shell.sh
+++ b/dev-tools/reformat-shell.sh
@@ -5,7 +5,7 @@
 
 set -u
 
-FORMAT_ARGS="--indent=4 --func-next-line --case-indent"
+FORMAT_ARGS="--simplify --indent=4 --func-next-line --case-indent"
 FORMAT_CMD="shfmt --list --write"
 
 # hardcoded to --posix due to .in filename and invalid shebang
diff --git a/tests/t_client.sh.in b/tests/t_client.sh.in
index 305441be..230a273 100755
--- a/tests/t_client.sh.in
+++ b/tests/t_client.sh.in
@@ -155,7 +155,7 @@
 fail()
 {
     output "FAIL: $@\n"
-    fail_count=$(($fail_count + 1))
+    fail_count=$((fail_count + 1))
 }
 
 # print "all interface IP addresses" + "all routes"
@@ -386,7 +386,7 @@
             ovpn_init_check=0
             ovpn_init_success=1
         fi
-        ovpn_init_check=$(($ovpn_init_check - 1))
+        ovpn_init_check=$((ovpn_init_check - 1))
     done
 
     opid=$(cat $pidfile)
diff --git a/tests/t_lpback.sh b/tests/t_lpback.sh
index 058206f..ec0a220 100755
--- a/tests/t_lpback.sh
+++ b/tests/t_lpback.sh
@@ -59,13 +59,13 @@
                 ;;
         esac
         e=1
-        tests_failed=$(($tests_failed + 1))
+        tests_failed=$((tests_failed + 1))
     else
         case $V in
             0 | 1) ;;       # no per-test output for 'OK'
             *) echo "OK" ;; # print all
         esac
-        tests_passed=$(($tests_passed + 1))
+        tests_passed=$((tests_passed + 1))
     fi
 }
 
diff --git a/tests/t_net.sh b/tests/t_net.sh
index 17e028e..d63f648 100755
--- a/tests/t_net.sh
+++ b/tests/t_net.sh
@@ -162,7 +162,7 @@
 # remove interface for good
 $RUN_SUDO ip link del $IFACE
 
-for i in $(seq $(($LAST_AUTO_TEST + 1)) ${LAST_TEST}); do
+for i in $(seq $((LAST_AUTO_TEST + 1)) ${LAST_TEST}); do
     $RUN_SUDO $UNIT_TEST $i
     if [ $? -ne 0 ]; then
         echo "unit-test $i errored out"
diff --git a/tests/t_server_null_client.sh b/tests/t_server_null_client.sh
index 3203cc2..9f4168b 100755
--- a/tests/t_server_null_client.sh
+++ b/tests/t_server_null_client.sh
@@ -164,7 +164,7 @@
             continue
         fi
         if $RUN_SUDO kill -0 $server_pid >/dev/null 2>&1; then
-            servers_up=$(($servers_up + 1))
+            servers_up=$((servers_up + 1))
         fi
     done