diff --git a/Makefile b/Makefile
index 32684463..48947a92 100644
--- a/Makefile
+++ b/Makefile
@@ -9,7 +9,7 @@ build:
 run:
 	# Copy test files
 	cp -a test/accounts-db/ postfix/
-	cp test/main.cf postfix/
+	cp test/runtime.main.cf postfix/
 	cp test/virtual postfix/
 	# Run containers
 	docker run -d --name mail \
@@ -63,5 +63,6 @@ tests:
 clean:
 	# Get default files back
 	git checkout postfix/accounts-db postfix/main.cf postfix/virtual
+	rm -f postfix/runtime.main.cf
 	# Remove running test containers
 	docker rm -f mail mail_pop3 mail_smtponly mail_fail2ban
diff --git a/start-mailserver.sh b/start-mailserver.sh
index 07818277..0ed36c68 100644
--- a/start-mailserver.sh
+++ b/start-mailserver.sh
@@ -230,13 +230,13 @@ case $DMS_SSL in
 
 esac
 
-if [ -f /tmp/postfix/main.cf ]; then
+if [ -f /tmp/postfix/runtime.main.cf ]; then
   while read line; do
     postconf -e "$line"
-  done < /tmp/postfix/main.cf
-  echo "Loaded '/tmp/postfix/main.cf'"
+  done < /tmp/postfix/runtime.main.cf
+  echo "Loaded '/tmp/postfix/runtime.main.cf'"
 else
-  echo "'/tmp/postfix/main.cf' not provided. No extra postfix settings loaded."
+  echo "'/tmp/postfix/runtime.main.cf' not provided. No extra postfix settings loaded."
 fi
 
 if [ ! -z "$SASL_PASSWORD" ]; then
diff --git a/test/main.cf b/test/runtime.main.cf
similarity index 100%
rename from test/main.cf
rename to test/runtime.main.cf
diff --git a/test/tests.bats b/test/tests.bats
index 47ceca9c..e7d07ac9 100644
--- a/test/tests.bats
+++ b/test/tests.bats
@@ -245,10 +245,10 @@
   [ "${lines[1]}" = "otherdomain.tld" ]
 }
 
-@test "checking postfix: main.cf overrides" {
-  run docker exec mail grep -q 'max_idle = 600s' /tmp/postfix/main.cf
+@test "checking postfix: runtime.main.cf overrides" {
+  run docker exec mail grep -q 'max_idle = 600s' /tmp/postfix/runtime.main.cf
   [ "$status" -eq 0 ]
-  run docker exec mail grep -q 'readme_directory = /tmp' /tmp/postfix/main.cf
+  run docker exec mail grep -q 'readme_directory = /tmp' /tmp/postfix/runtime.main.cf
   [ "$status" -eq 0 ]
 }