diff --git a/src/unix/taskbarx11.cpp b/src/unix/taskbarx11.cpp
index 6c3af3359f..ced3b5e059 100644
--- a/src/unix/taskbarx11.cpp
+++ b/src/unix/taskbarx11.cpp
@@ -264,7 +264,8 @@ wxTaskBarIcon::~wxTaskBarIcon()
 {
     if (m_iconWnd)
     {
-        m_iconWnd->Disconnect(wxEVT_DESTROY, NULL, NULL, this);
+        m_iconWnd->Disconnect(
+            wxEVT_DESTROY, wxObjectEventFunction(NULL), NULL, this);
         RemoveIcon();
     }
 }