diff --git a/src/msw/glcanvas.cpp b/src/msw/glcanvas.cpp
index 5863b71270..edc53bc677 100644
--- a/src/msw/glcanvas.cpp
+++ b/src/msw/glcanvas.cpp
@@ -552,6 +552,7 @@ wxIMPLEMENT_CLASS(wxGLContext, wxObject);
 wxGLContext::wxGLContext(wxGLCanvas *win,
                          const wxGLContext *other,
                          const wxGLContextAttrs *ctxAttrs)
+    : m_glContext(NULL)
 {
     const int* contextAttribs = NULL;
     bool needsARB = false;
@@ -614,7 +615,10 @@ wxGLContext::wxGLContext(wxGLCanvas *win,
 wxGLContext::~wxGLContext()
 {
     // note that it's ok to delete the context even if it's the current one
-    wglDeleteContext(m_glContext);
+    if ( m_glContext )
+    {
+        wglDeleteContext(m_glContext);
+    }
 }
 
 bool wxGLContext::SetCurrent(const wxGLCanvas& win) const
diff --git a/src/osx/glcanvas_osx.cpp b/src/osx/glcanvas_osx.cpp
index a91f748533..32630e4c80 100644
--- a/src/osx/glcanvas_osx.cpp
+++ b/src/osx/glcanvas_osx.cpp
@@ -359,6 +359,7 @@ wxGLAttributes& wxGLAttributes::Defaults()
 wxGLContext::wxGLContext(wxGLCanvas *win,
                          const wxGLContext *other,
                          const wxGLContextAttrs *ctxAttrs)
+    : m_glContext(NULL)
 {
     const int* contextAttribs = NULL;
     int ctxSize = 0;
diff --git a/src/unix/glx11.cpp b/src/unix/glx11.cpp
index 52f756e259..65346010c4 100644
--- a/src/unix/glx11.cpp
+++ b/src/unix/glx11.cpp
@@ -454,6 +454,7 @@ wxIMPLEMENT_CLASS(wxGLContext, wxObject);
 wxGLContext::wxGLContext(wxGLCanvas *win,
                          const wxGLContext *other,
                          const wxGLContextAttrs *ctxAttrs)
+    : m_glContext(NULL)
 {
     const int* contextAttribs = NULL;
     Bool x11Direct = True;