diff --git a/test/tests/parallel/set1/spam_virus/amavis.bats b/test/tests/parallel/set1/spam_virus/amavis.bats
index d7a59cb2..467d5207 100644
--- a/test/tests/parallel/set1/spam_virus/amavis.bats
+++ b/test/tests/parallel/set1/spam_virus/amavis.bats
@@ -14,6 +14,7 @@ function setup_file() {
     --env ENABLE_AMAVIS=1
     --env AMAVIS_LOGLEVEL=2
     --env ENABLE_SPAMASSASSIN=1
+    --env SPAM_SUBJECT='***SPAM*** '
   )
   _common_container_setup 'CUSTOM_SETUP_ARGUMENTS'
 
diff --git a/test/tests/parallel/set1/spam_virus/undef_spam_subject.bats b/test/tests/parallel/set1/spam_virus/undef_spam_subject.bats
index 9788f6a6..c55a6dba 100644
--- a/test/tests/parallel/set1/spam_virus/undef_spam_subject.bats
+++ b/test/tests/parallel/set1/spam_virus/undef_spam_subject.bats
@@ -9,12 +9,11 @@ CONTAINER_NAME=${CONTAINER2_NAME}
 
 function teardown() { _default_teardown ; }
 
-@test "'SPAM_SUBJECT=undef' should update Amavis config" {
+@test "Empty 'SPAM_SUBJECT' should set correct value in Amavis config" {
   export CONTAINER_NAME=${CONTAINER1_NAME}
   local CUSTOM_SETUP_ARGUMENTS=(
     --env ENABLE_AMAVIS=1
     --env ENABLE_SPAMASSASSIN=1
-    --env SPAM_SUBJECT='undef'
   )
   _init_with_defaults
   _common_container_setup 'CUSTOM_SETUP_ARGUMENTS'
@@ -36,7 +35,7 @@ function teardown() { _default_teardown ; }
     --env SA_TAG=-5.0
     --env SA_TAG2=2.0
     --env SA_KILL=3.0
-    --env SPAM_SUBJECT="SPAM: "
+    --env SPAM_SUBJECT='SPAM: '
     --env VIRUSMAILS_DELETE_DELAY=7
     --env ENABLE_SRS=1
     --env ENABLE_MANAGESIEVE=1