diff --git a/common/widgets/grid_color_swatch_helpers.cpp b/common/widgets/grid_color_swatch_helpers.cpp
index e683187eda..344493a3be 100644
--- a/common/widgets/grid_color_swatch_helpers.cpp
+++ b/common/widgets/grid_color_swatch_helpers.cpp
@@ -116,7 +116,7 @@ void GRID_CELL_COLOR_RENDERER::Draw( wxGrid& aGrid, wxGridCellAttr& aAttr, wxDC&
 
 void GRID_CELL_COLOR_RENDERER::OnDarkModeToggle()
 {
-    m_checkerboardBg = m_parent->GetBackgroundColour();
+    m_checkerboardBg = m_parent ? m_parent->GetBackgroundColour() : wxSystemSettings::GetColour( wxSYS_COLOUR_WINDOW );
 }
 
 
diff --git a/pcbnew/pcb_base_edit_frame.cpp b/pcbnew/pcb_base_edit_frame.cpp
index 04704fe7b3..b07d5ab932 100644
--- a/pcbnew/pcb_base_edit_frame.cpp
+++ b/pcbnew/pcb_base_edit_frame.cpp
@@ -60,6 +60,10 @@ PCB_BASE_EDIT_FRAME::PCB_BASE_EDIT_FRAME( KIWAY* aKiway, wxWindow* aParent,
 {
     m_darkMode = KIPLATFORM::UI::IsDarkTheme();
 
+    // Do not register the idle event handler if we are running in headless mode.
+    if( !wxApp::GetGUIInstance() )
+        return;
+
     Bind( wxEVT_IDLE,
           [this]( wxIdleEvent& aEvent )
           {