diff --git a/introspection_response_writer.go b/introspection_response_writer.go
index 5711d2b6..e0a3763e 100644
--- a/introspection_response_writer.go
+++ b/introspection_response_writer.go
@@ -179,6 +179,10 @@ func (f *Fosite) WriteIntrospectionError(ctx context.Context, rw http.ResponseWr
 //	  "active": false
 //	}
 func (f *Fosite) WriteIntrospectionResponse(ctx context.Context, rw http.ResponseWriter, r IntrospectionResponder) {
+	rw.Header().Set("Content-Type", "application/json;charset=UTF-8")
+	rw.Header().Set("Cache-Control", "no-store")
+	rw.Header().Set("Pragma", "no-cache")
+
 	if !r.IsActive() {
 		_ = json.NewEncoder(rw).Encode(&struct {
 			Active bool `json:"active"`
@@ -226,8 +230,5 @@ func (f *Fosite) WriteIntrospectionResponse(ctx context.Context, rw http.Respons
 		response["username"] = r.GetAccessRequester().GetSession().GetUsername()
 	}
 
-	rw.Header().Set("Content-Type", "application/json;charset=UTF-8")
-	rw.Header().Set("Cache-Control", "no-store")
-	rw.Header().Set("Pragma", "no-cache")
 	_ = json.NewEncoder(rw).Encode(response)
 }
diff --git a/introspection_response_writer_test.go b/introspection_response_writer_test.go
index b1738cef..a7754486 100644
--- a/introspection_response_writer_test.go
+++ b/introspection_response_writer_test.go
@@ -53,6 +53,7 @@ func TestWriteIntrospectionResponse(t *testing.T) {
 
 	rw := internal.NewMockResponseWriter(c)
 	rw.EXPECT().Write(gomock.Any()).AnyTimes()
+	rw.EXPECT().Header().AnyTimes().Return(http.Header{})
 	f.WriteIntrospectionResponse(context.Background(), rw, &IntrospectionResponse{
 		AccessRequester: NewAccessRequest(nil),
 	})