diff --git a/include/wx/any.h b/include/wx/any.h
index 4bf9b0eef4..3d057c8a60 100644
--- a/include/wx/any.h
+++ b/include/wx/any.h
@@ -730,6 +730,7 @@ public:
     wxAny()
     {
         m_type = wxAnyNullValueType;
+        m_buffer = { 0 };
     }
 
     /**
diff --git a/include/wx/event.h b/include/wx/event.h
index 3b5a975c01..fd25c7a1ca 100644
--- a/include/wx/event.h
+++ b/include/wx/event.h
@@ -244,7 +244,7 @@ private:
     wxEventFunction m_method;
 
     // Provide a dummy default ctor for type info purposes
-    wxObjectEventFunctor() { }
+    wxObjectEventFunctor() : m_handler(NULL), m_method(NULL) { }
 
     WX_DECLARE_TYPEINFO_INLINE(wxObjectEventFunctor)
 };
diff --git a/include/wx/gauge.h b/include/wx/gauge.h
index d89f089131..b1ddac7769 100644
--- a/include/wx/gauge.h
+++ b/include/wx/gauge.h
@@ -52,6 +52,9 @@ class WXDLLIMPEXP_CORE wxGaugeBase : public wxControl
 {
 public:
     wxGaugeBase() : m_rangeMax(0), m_gaugePos(0),
+#if wxGAUGE_EMULATE_INDETERMINATE_MODE
+        m_nDirection(wxRIGHT),
+#endif
         m_appProgressIndicator(NULL) { }
 
     virtual ~wxGaugeBase();
diff --git a/include/wx/generic/choicdgg.h b/include/wx/generic/choicdgg.h
index 114d666230..152b581c81 100644
--- a/include/wx/generic/choicdgg.h
+++ b/include/wx/generic/choicdgg.h
@@ -33,7 +33,7 @@ class WXDLLIMPEXP_FWD_CORE wxListBoxBase;
 class WXDLLIMPEXP_CORE wxAnyChoiceDialog : public wxDialog
 {
 public:
-    wxAnyChoiceDialog() { }
+    wxAnyChoiceDialog() : m_listbox(NULL) { }
 
     wxAnyChoiceDialog(wxWindow *parent,
                       const wxString& message,
diff --git a/include/wx/generic/textdlgg.h b/include/wx/generic/textdlgg.h
index a3749844fd..9aee847083 100644
--- a/include/wx/generic/textdlgg.h
+++ b/include/wx/generic/textdlgg.h
@@ -39,6 +39,7 @@ public:
     wxTextEntryDialog()
     {
         m_textctrl = NULL;
+        m_dialogStyle = 0;
     }
 
     wxTextEntryDialog(wxWindow *parent,
diff --git a/include/wx/list.h b/include/wx/list.h
index cc58fe04f8..3c3ddd896e 100644
--- a/include/wx/list.h
+++ b/include/wx/list.h
@@ -333,7 +333,7 @@ class WXDLLIMPEXP_BASE wxListKey
 public:
     // implicit ctors
     wxListKey() : m_keyType(wxKEY_NONE)
-        { }
+        { m_key.integer = 0; }
     wxListKey(long i) : m_keyType(wxKEY_INTEGER)
         { m_key.integer = i; }
     wxListKey(const wxString& s) : m_keyType(wxKEY_STRING)
diff --git a/include/wx/msw/checkbox.h b/include/wx/msw/checkbox.h
index afecb4baf9..f8b12c1f3b 100644
--- a/include/wx/msw/checkbox.h
+++ b/include/wx/msw/checkbox.h
@@ -17,7 +17,7 @@
 class WXDLLIMPEXP_CORE wxCheckBox : public wxMSWOwnerDrawnButton<wxCheckBoxBase>
 {
 public:
-    wxCheckBox() { }
+    wxCheckBox() : m_state(wxCHK_UNCHECKED) { }
     wxCheckBox(wxWindow *parent,
                wxWindowID id,
                const wxString& label,
diff --git a/include/wx/strconv.h b/include/wx/strconv.h
index d344a5a911..f6088e10c0 100644
--- a/include/wx/strconv.h
+++ b/include/wx/strconv.h
@@ -288,7 +288,7 @@ private:
 
     public:
         // the initial state is direct
-        DecoderState() { mode = Direct; }
+        DecoderState() { mode = Direct; accum = bit = msb = 0; }
 
         // switch to/from shifted mode
         void ToDirect() { mode = Direct; }
@@ -317,7 +317,7 @@ private:
         Mode mode;
 
     public:
-        EncoderState() { mode = Direct; }
+        EncoderState() { mode = Direct; accum = bit = 0; }
 
         void ToDirect() { mode = Direct; }
         void ToShifted() { mode = Shifted; accum = bit = 0; }
diff --git a/include/wx/string.h b/include/wx/string.h
index 6e579ed616..88bbe43fe0 100644
--- a/include/wx/string.h
+++ b/include/wx/string.h
@@ -3379,7 +3379,7 @@ private:
   {
       // notice that there is no need to initialize m_len here as it's unused
       // as long as m_str is NULL
-      ConvertedBuffer() : m_str(NULL) {}
+      ConvertedBuffer() : m_str(NULL), m_len(0) {}
       ~ConvertedBuffer()
           { free(m_str); }