diff --git a/CHANGELOG.md b/CHANGELOG.md
index bc7e6765..cb2dd29a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,8 @@
+## v0.22.15-WIP
+
+- Added `tests.TestMailer` mutex to minimize the data race warnings during tests ([#5157](https://github.com/pocketbase/pocketbase/issues/5157)).
+
+
 ## v0.22.14
 
 - Added OAuth2 POST redirect support (in case of `response_mode=form_post`) to allow specifying scopes for the Apple OAuth2 integration.
diff --git a/tests/mailer.go b/tests/mailer.go
index 82d97c1f..9672ad8b 100644
--- a/tests/mailer.go
+++ b/tests/mailer.go
@@ -1,6 +1,8 @@
 package tests
 
 import (
+	"sync"
+
 	"github.com/pocketbase/pocketbase/tools/mailer"
 )
 
@@ -8,6 +10,8 @@ var _ mailer.Mailer = (*TestMailer)(nil)
 
 // TestMailer is a mock `mailer.Mailer` implementation.
 type TestMailer struct {
+	mux sync.Mutex
+
 	TotalSend   int
 	LastMessage mailer.Message
 
@@ -17,6 +21,9 @@ type TestMailer struct {
 
 // Reset clears any previously test collected data.
 func (tm *TestMailer) Reset() {
+	tm.mux.Lock()
+	defer tm.mux.Unlock()
+
 	tm.TotalSend = 0
 	tm.LastMessage = mailer.Message{}
 	tm.SentMessages = nil
@@ -24,6 +31,9 @@ func (tm *TestMailer) Reset() {
 
 // Send implements `mailer.Mailer` interface.
 func (tm *TestMailer) Send(m *mailer.Message) error {
+	tm.mux.Lock()
+	defer tm.mux.Unlock()
+
 	tm.TotalSend++
 	tm.LastMessage = *m
 	tm.SentMessages = append(tm.SentMessages, tm.LastMessage)