diff --git a/core/modules/user/src/Plugin/LanguageNegotiation/LanguageNegotiationUserAdmin.php b/core/modules/user/src/Plugin/LanguageNegotiation/LanguageNegotiationUserAdmin.php
index c00509f..d559f03 100644
--- a/core/modules/user/src/Plugin/LanguageNegotiation/LanguageNegotiationUserAdmin.php
+++ b/core/modules/user/src/Plugin/LanguageNegotiation/LanguageNegotiationUserAdmin.php
@@ -120,7 +120,7 @@ public function getLangcode(Request $request = NULL) {
    */
   protected function isAdminPath(Request $request) {
     $result = FALSE;
-    if ($request && $this->adminContext) {
+    if ($request && $this->adminContext && $request->getMethod() == 'GET') {
       // If called from an event subscriber, the request may not have the route
       // object yet (it is still being built), so use the router to look up
       // based on the path.