diff --git a/src/lib-sieve/plugins/vacation/cmd-vacation.c b/src/lib-sieve/plugins/vacation/cmd-vacation.c
index 257841cf2a8200fa75a761f5879ff58719c31137..91d2e71b1696d7a2f0ff4d7eec114d7ad3209dee 100644
--- a/src/lib-sieve/plugins/vacation/cmd-vacation.c
+++ b/src/lib-sieve/plugins/vacation/cmd-vacation.c
@@ -891,7 +891,7 @@ _msg_address_equals(const struct message_address *addr1,
 
 	i_assert(addr1->mailbox != NULL);
 	return (smtp_address_init_from_msg(&saddr, addr1) >= 0 &&
-		smtp_address_equals(addr2, &saddr));
+		smtp_address_equals_icase(addr2, &saddr));
 }
 
 static inline bool
@@ -1276,7 +1276,7 @@ act_vacation_commit(const struct sieve_action_exec_env *aenv,
 
 	/* Are we perhaps trying to respond to ourselves ?
 	 */
-	if (smtp_address_equals(sender, recipient)) {
+	if (smtp_address_equals_icase(sender, recipient)) {
 		sieve_result_global_log(
 			aenv, "discarded vacation reply to own address <%s>",
 			smtp_address_encode(sender));
@@ -1290,7 +1290,7 @@ act_vacation_commit(const struct sieve_action_exec_env *aenv,
 
 		alt_address = ctx->addresses;
 		while (*alt_address != NULL) {
-			if (smtp_address_equals(sender, *alt_address)) {
+			if (smtp_address_equals_icase(sender, *alt_address)) {
 				sieve_result_global_log(
 					aenv,
 					"discarded vacation reply to own address <%s> "
diff --git a/tests/extensions/vacation/reply.svtest b/tests/extensions/vacation/reply.svtest
index 49061beb78590ef78121a781ff4a531f1fe5cf43..55cc58d4fe2838d74e7905e3551791afbff51e48 100644
--- a/tests/extensions/vacation/reply.svtest
+++ b/tests/extensions/vacation/reply.svtest
@@ -396,6 +396,36 @@ test "Reply for :addresses" {
 	}
 }
 
+/*
+ * Reply for :addresses (case sensitivity)
+ */
+
+test_result_reset;
+
+test_set "message" text:
+From: timo@example.com
+To: Stephan.Bosch@example.com
+Subject: Frop!
+
+Frop!
+.
+;
+
+test_set "envelope.from" "timo@example.com";
+test_set "envelope.to" "stephan@example.com";
+
+test "Reply for :addresses (case sensitivity)" {
+	vacation :addresses "stephan.bosch@example.com" "I am gone";
+
+	if not test_result_execute {
+		test_fail "failed to execute vacation";
+	}
+
+	if not test_message :smtp 0 {
+		test_fail "vacation did not reply";
+	}
+}
+
 /*
  * Reply for original recipient
  */