diff --git a/context.go b/context.go
index c2f4d05..969ea8c 100644
--- a/context.go
+++ b/context.go
@@ -3,6 +3,7 @@ package httplog
 import (
 	"context"
 	"log/slog"
+	"sync"
 )
 
 const (
@@ -15,16 +16,35 @@ func (c *ctxKeyLogAttrs) String() string {
 	return "httplog attrs context"
 }
 
+type logData struct {
+	mu    sync.RWMutex
+	attrs []slog.Attr
+}
+
 // SetAttrs sets the attributes on the request log.
 func SetAttrs(ctx context.Context, attrs ...slog.Attr) {
-	if ptr, ok := ctx.Value(ctxKeyLogAttrs{}).(*[]slog.Attr); ok && ptr != nil {
-		*ptr = append(*ptr, attrs...)
+	if ptr, ok := ctx.Value(ctxKeyLogAttrs{}).(*logData); ok && ptr != nil {
+		ptr.mu.Lock()
+		defer ptr.mu.Unlock()
+		ptr.attrs = append(ptr.attrs, attrs...)
+	}
+}
+
+func lockData(ctx context.Context) {
+	if ptr, ok := ctx.Value(ctxKeyLogAttrs{}).(*logData); ok && ptr != nil {
+		ptr.mu.RLock()
+	}
+}
+
+func unlockData(ctx context.Context) {
+	if ptr, ok := ctx.Value(ctxKeyLogAttrs{}).(*logData); ok && ptr != nil {
+		ptr.mu.RUnlock()
 	}
 }
 
 func getAttrs(ctx context.Context) []slog.Attr {
-	if ptr, ok := ctx.Value(ctxKeyLogAttrs{}).(*[]slog.Attr); ok && ptr != nil {
-		return *ptr
+	if ptr, ok := ctx.Value(ctxKeyLogAttrs{}).(*logData); ok && ptr != nil {
+		return ptr.attrs
 	}
 
 	return nil
diff --git a/middleware.go b/middleware.go
index a31f3d8..29b6150 100644
--- a/middleware.go
+++ b/middleware.go
@@ -36,7 +36,7 @@ func RequestLogger(logger *slog.Logger, o *Options) func(http.Handler) http.Hand
 
 	return func(next http.Handler) http.Handler {
 		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-			ctx := context.WithValue(r.Context(), ctxKeyLogAttrs{}, &[]slog.Attr{})
+			ctx := context.WithValue(r.Context(), ctxKeyLogAttrs{}, &logData{})
 
 			logReqBody := o.LogRequestBody != nil && o.LogRequestBody(r)
 			logRespBody := o.LogResponseBody != nil && o.LogResponseBody(r)
@@ -56,6 +56,9 @@ func RequestLogger(logger *slog.Logger, o *Options) func(http.Handler) http.Hand
 			start := time.Now()
 
 			defer func() {
+				lockData(ctx)
+				defer unlockData(ctx)
+
 				var logAttrs []slog.Attr
 
 				if rec := recover(); rec != nil {