diff --git a/src/frontends/wx/wx_frame.cpp b/src/frontends/wx/wx_frame.cpp
index 88689e7..f634542 100644
--- a/src/frontends/wx/wx_frame.cpp
+++ b/src/frontends/wx/wx_frame.cpp
@@ -170,6 +170,13 @@ EssimFrame::EssimFrame(WxFrontend &fe)
     root->Add(log_, 1, wxEXPAND | wxALL, 4);
     panel->SetSizer(root);
 
+    // Drive the panel from a frame sizer so it fills the client area and
+    // re-lays-out on every resize (the implicit single-child fill is not
+    // reliable here — without this the log keeps its size when the window grows).
+    auto *frame_sizer = new wxBoxSizer(wxVERTICAL);
+    frame_sizer->Add(panel, 1, wxEXPAND);
+    SetSizer(frame_sizer);
+
     Bind(wxEVT_MENU, &EssimFrame::OnLoad,    this, ID_LOAD);
     Bind(wxEVT_MENU, &EssimFrame::OnRestore, this, ID_RESTORE);
     Bind(wxEVT_MENU, &EssimFrame::OnSave,    this, ID_SAVE);