diff --git a/auth/jwt/middleware_test.go b/auth/jwt/middleware_test.go
index 8a45201..efaaf2d 100644
--- a/auth/jwt/middleware_test.go
+++ b/auth/jwt/middleware_test.go
@@ -2,6 +2,7 @@
 
 import (
 	"context"
+	"sync"
 	"testing"
 	"time"
 
@@ -199,3 +200,22 @@
 		t.Fatalf("JWT customClaims.MyProperty did not match: expecting %s got %s", myProperty, custCl.MyProperty)
 	}
 }
+
+func TestIssue562(t *testing.T) {
+	var (
+		kf  = func(token *jwt.Token) (interface{}, error) { return []byte("secret"), nil }
+		e   = NewParser(kf, jwt.SigningMethodHS256, jwt.MapClaims{})(endpoint.Nop)
+		key = JWTTokenContextKey
+		val = "eyJhbGciOiJIUzI1NiIsImtpZCI6ImtpZCIsInR5cCI6IkpXVCJ9.eyJ1c2VyIjoiZ28ta2l0In0.14M2VmYyApdSlV_LZ88ajjwuaLeIFplB8JpyNy0A19E"
+		ctx = context.WithValue(context.Background(), key, val)
+	)
+	wg := sync.WaitGroup{}
+	for i := 0; i < 100; i++ {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			e(ctx, struct{}{}) // fatal error: concurrent map read and map write
+		}()
+	}
+	wg.Wait()
+}