diff --git a/src/msw/helpchm.cpp b/src/msw/helpchm.cpp
index 4e95ce7ad8..8ce00f1237 100644
--- a/src/msw/helpchm.cpp
+++ b/src/msw/helpchm.cpp
@@ -242,6 +242,7 @@ wxString wxCHMHelpController::GetValidFilename(const wxString& file) const
 
 wxCHMHelpController::~wxCHMHelpController()
 {
+    gs_htmlHelp(GetSuitableHWND(), 0, HH_CLOSE_ALL, 0L);
     UnloadHtmlHelpLibrary();
 }