diff --git a/src/html/helpfrm.cpp b/src/html/helpfrm.cpp
index f9efaaa048..0df2ab25b7 100644
--- a/src/html/helpfrm.cpp
+++ b/src/html/helpfrm.cpp
@@ -462,6 +462,7 @@ wxHtmlHelpFrame::~wxHtmlHelpFrame()
         delete m_Data;
     if (m_NormalFonts) delete m_NormalFonts;
     if (m_FixedFonts) delete m_FixedFonts;
+    if (m_PagesHash) delete m_PagesHash;
 }