diff --git a/test/helper/sending.bash b/test/helper/sending.bash
index 7c52e3bb..df7d06d8 100644
--- a/test/helper/sending.bash
+++ b/test/helper/sending.bash
@@ -27,7 +27,7 @@
 function _send_email() {
   [[ -v CONTAINER_NAME ]] || return 1
 
-  local HELO='mail.external.tld'
+  local EHLO='mail.external.tld'
   local FROM='user@external.tld'
   local TO='user1@localhost.localdomain'
   local SERVER='0.0.0.0'
@@ -37,7 +37,7 @@ function _send_email() {
 
   while [[ ${#} -gt 0 ]]; do
     case "${1}" in
-      ( '--helo' )   HELO=${2:?--helo given but no argument}     ; shift 2 ;;
+      ( '--ehlo' )   EHLO=${2:?--ehlo given but no argument}     ; shift 2 ;;
       ( '--from' )   FROM=${2:?--from given but no argument}     ; shift 2 ;;
       ( '--to' )     TO=${2:?--to given but no argument}         ; shift 2 ;;
       ( '--server' ) SERVER=${2:?--server given but no argument} ; shift 2 ;;
diff --git a/test/tests/parallel/set3/mta/smtp_delivery.bats b/test/tests/parallel/set3/mta/smtp_delivery.bats
index 0fb30bdb..90e82f36 100644
--- a/test/tests/parallel/set3/mta/smtp_delivery.bats
+++ b/test/tests/parallel/set3/mta/smtp_delivery.bats
@@ -262,7 +262,7 @@ function setup_file() {
   # - This query requires a EHLO greeting to the destination server.
   # - HELO is treated as EHLO when protocol is ESMTP.
   swaks \
-    --helo mail.external.tld \
+    --ehlo mail.external.tld \
     --protocol ESMTP \
     --server mail.example.test \
     --quit-after FIRST-HELO
diff --git a/test/tests/parallel/set3/mta/smtponly.bats b/test/tests/parallel/set3/mta/smtponly.bats
index db5b5058..0ff08be3 100644
--- a/test/tests/parallel/set3/mta/smtponly.bats
+++ b/test/tests/parallel/set3/mta/smtponly.bats
@@ -33,7 +33,7 @@ function teardown_file() { _default_teardown ; }
 
   # it looks as if someone tries to send mail to another domain outside of DMS
   _send_email \
-    --helo mail.origin.test \
+    --ehlo mail.origin.test \
     --protocol SSMTPA \
     --server mail.origin.test \
     --from user@origin.test \
diff --git a/test/tests/serial/mail_with_ldap.bats b/test/tests/serial/mail_with_ldap.bats
index 4903e8d4..8cab4ffc 100644
--- a/test/tests/serial/mail_with_ldap.bats
+++ b/test/tests/serial/mail_with_ldap.bats
@@ -331,7 +331,7 @@ function teardown() {
     --port 465 -tlsc --auth LOGIN \
     --auth-user some.user@localhost.localdomain \
     --auth-password secret \
-    --helo mail \
+    --ehlo mail \
     --from ldap@localhost.localdomain \
     --data 'auth/ldap-smtp-auth-spoofed'
   assert_output --partial 'Sender address rejected: not owned by user'
@@ -342,7 +342,7 @@ function teardown() {
     --port 465 -tlsc --auth LOGIN \
     --auth-user some.user@localhost.localdomain \
     --auth-password secret \
-    --helo mail \
+    --ehlo mail \
     --from postmaster@localhost.localdomain \
     --to some.user@localhost.localdomain \
     --data 'auth/ldap-smtp-auth-spoofed-alias'
@@ -358,7 +358,7 @@ function teardown() {
     --port 465 -tlsc --auth LOGIN \
     --auth-user some.user.email@localhost.localdomain \
     --auth-password secret \
-    --helo mail \
+    --ehlo mail \
     --from randomspoofedaddress@localhost.localdomain \
     --to some.user@localhost.localdomain \
     --data 'auth/ldap-smtp-auth-spoofed-sender-with-filter-exception'
diff --git a/test/tests/serial/tests.bats b/test/tests/serial/tests.bats
index 505b0242..f3f87d10 100644
--- a/test/tests/serial/tests.bats
+++ b/test/tests/serial/tests.bats
@@ -295,7 +295,7 @@ EOF
     --port 465 -tlsc --auth LOGIN \
     --auth-user added@localhost.localdomain \
     --auth-password mypassword \
-    --helo mail \
+    --ehlo mail \
     --from user2@localhost.localdomain \
     --data 'auth/added-smtp-auth-spoofed'
   assert_output --partial 'Sender address rejected: not owned by user'
@@ -311,7 +311,7 @@ EOF
     --port 465 -tlsc --auth LOGIN \
     --auth-user user1@localhost.localdomain \
     --auth-password mypassword \
-    --helo mail \
+    --ehlo mail \
     --from alias1@localhost.localdomain \
     --data 'auth/added-smtp-auth-spoofed-alias'
   assert_success