diff --git a/api/middleware.go b/api/middleware.go
index c350b1c..27202c3 100644
--- a/api/middleware.go
+++ b/api/middleware.go
@@ -36,6 +36,7 @@ func mwBasicAuth(auther auth.Authenticator) gin.HandlerFunc {
 		}
 		u, p, _ := c.Request.BasicAuth()
 		if _, ok := auther.Authenticate(c, u, p); !ok {
+			c.Writer.Header().Set("WWW-Authenticate", "Basic")
 			c.AbortWithStatus(http.StatusUnauthorized)
 		}
 	}