diff --git a/tests/sizers/gridsizer.cpp b/tests/sizers/gridsizer.cpp
index a3cd38c61b..2497025d97 100644
--- a/tests/sizers/gridsizer.cpp
+++ b/tests/sizers/gridsizer.cpp
@@ -22,59 +22,79 @@
 #include "asserthelper.h"
 
 // ----------------------------------------------------------------------------
-// test class
+// test fixtures
 // ----------------------------------------------------------------------------
 
-class GridSizerTestCase
+// Base class for the two fixtures below.
+class GridSizerTestCaseBase
 {
 protected:
-    GridSizerTestCase();
-    ~GridSizerTestCase();
+    explicit GridSizerTestCaseBase(wxGridSizer* sizer);
+    ~GridSizerTestCaseBase();
     // Clear the current sizer contents and add the specified windows to it,
     // using the same flags for all of them.
     void SetChildren(const wxVector<wxWindow*>& children,
                      const wxSizerFlags& flags);
 
     wxWindow *m_win;
-    wxFlexGridSizer *m_sizer;
+    wxGridSizer* const m_sizerBase;
 
-    wxDECLARE_NO_COPY_CLASS(GridSizerTestCase);
+    wxDECLARE_NO_COPY_CLASS(GridSizerTestCaseBase);
+};
+
+class GridSizerTestCase : public GridSizerTestCaseBase
+{
+protected:
+    GridSizerTestCase()
+        : GridSizerTestCaseBase(m_sizer = new wxGridSizer(2))
+    {
+    }
+
+    wxGridSizer *m_sizer;
+};
+
+class FlexGridSizerTestCase : public GridSizerTestCaseBase
+{
+protected:
+    FlexGridSizerTestCase()
+        : GridSizerTestCaseBase(m_sizer = new wxFlexGridSizer(2))
+    {
+    }
+
+    wxFlexGridSizer *m_sizer;
 };
 
 // ----------------------------------------------------------------------------
 // test initialization
 // ----------------------------------------------------------------------------
 
-GridSizerTestCase::GridSizerTestCase()
+GridSizerTestCaseBase::GridSizerTestCaseBase(wxGridSizer* sizer)
+    : m_sizerBase(sizer)
 {
     m_win = new wxWindow(wxTheApp->GetTopWindow(), wxID_ANY);
     m_win->SetClientSize(127, 35);
 
-    m_sizer = new wxFlexGridSizer(2);
-    m_win->SetSizer(m_sizer);
+    m_win->SetSizer(m_sizerBase);
 }
 
-GridSizerTestCase::~GridSizerTestCase()
+GridSizerTestCaseBase::~GridSizerTestCaseBase()
 {
     delete m_win;
-    m_win = nullptr;
-
-    m_sizer = nullptr;
 }
 
 // ----------------------------------------------------------------------------
 // helpers
 // ----------------------------------------------------------------------------
 
-void GridSizerTestCase::SetChildren(const wxVector<wxWindow*>& children,
-                                    const wxSizerFlags& flags)
+void GridSizerTestCaseBase::SetChildren(const wxVector<wxWindow*>& children,
+                                        const wxSizerFlags& flags)
 {
-    m_sizer->Clear();
+    m_sizerBase->Clear();
     for ( wxVector<wxWindow*>::const_iterator i = children.begin();
           i != children.end();
           ++i )
     {
-        m_sizer->Add(*i, flags);
+        m_sizerBase->Add(*i, flags);
     }
 
     m_win->Layout();
@@ -87,6 +107,25 @@ void GridSizerTestCase::SetChildren(const wxVector<wxWindow*>& children,
 TEST_CASE_METHOD(GridSizerTestCase,
                  "wxGridSizer::Layout",
                  "[grid-sizer][sizer]")
+{
+    const wxSize sizeTotal = m_win->GetClientSize();
+    const wxSize sizeChild(sizeTotal.x / 2, sizeTotal.y / 2);
+
+    wxVector<wxWindow*> children;
+    for ( int n = 0; n < 3; n++ )
+    {
+        children.push_back(new wxWindow(m_win, wxID_ANY));
+    }
+
+    SetChildren(children, wxSizerFlags().Expand());
+    CHECK( children[0]->GetRect() == wxRect(wxPoint(0, 0), sizeChild) );
+    CHECK( children[1]->GetRect() == wxRect(wxPoint(sizeChild.x, 0), sizeChild) );
+    CHECK( children[2]->GetRect() == wxRect(wxPoint(0, sizeChild.y), sizeChild) );
+}
+
+TEST_CASE_METHOD(FlexGridSizerTestCase,
+                 "wxFlexGridSizer::Layout",
+                 "[grid-sizer][sizer]")
 {
     const wxSize sizeTotal = m_win->GetClientSize();
     const wxSize sizeChild(sizeTotal.x / 4, sizeTotal.y / 4);
@@ -180,8 +219,8 @@ TEST_CASE_METHOD(GridSizerTestCase,
     );
 }
 
-TEST_CASE_METHOD(GridSizerTestCase,
-                 "wxGridSizer::GrowMode",
+TEST_CASE_METHOD(FlexGridSizerTestCase,
+                 "wxFlexGridSizer::GrowMode",
                  "[grid-sizer][sizer]")
 {
     wxVector<wxWindow*> children;