diff --git a/3d-viewer/3d_viewer/eda_3d_viewer_frame.cpp b/3d-viewer/3d_viewer/eda_3d_viewer_frame.cpp
index 52bffd979e..ff09ced869 100644
--- a/3d-viewer/3d_viewer/eda_3d_viewer_frame.cpp
+++ b/3d-viewer/3d_viewer/eda_3d_viewer_frame.cpp
@@ -396,7 +396,7 @@ void EDA_3D_VIEWER_FRAME::NewDisplay( bool aForceImmediateRedraw )
 
     // After the ReloadRequest call, the refresh often takes a bit of time,
     // and it is made here only on request.
-    if( aForceImmediateRedraw )
+    if( m_canvas && aForceImmediateRedraw )
         m_canvas->Refresh();
 }
 
diff --git a/3d-viewer/dialogs/appearance_controls_3D.cpp b/3d-viewer/dialogs/appearance_controls_3D.cpp
index 08088b4a77..0435381dc1 100644
--- a/3d-viewer/dialogs/appearance_controls_3D.cpp
+++ b/3d-viewer/dialogs/appearance_controls_3D.cpp
@@ -81,7 +81,8 @@ APPEARANCE_CONTROLS_3D::APPEARANCE_CONTROLS_3D( EDA_3D_VIEWER_FRAME* aParent,
                                                 wxWindow* aFocusOwner ) :
         APPEARANCE_CONTROLS_3D_BASE( aParent ),
         m_frame( aParent ),
-        m_focusOwner( aFocusOwner )
+        m_focusOwner( aFocusOwner ),
+        m_lastSelectedViewport( nullptr )
 {
     DPI_SCALING dpi( nullptr, m_frame );
 
diff --git a/common/jobs/job_dispatcher.cpp b/common/jobs/job_dispatcher.cpp
index 6623f7945e..65b92602d8 100644
--- a/common/jobs/job_dispatcher.cpp
+++ b/common/jobs/job_dispatcher.cpp
@@ -27,6 +27,7 @@
 JOB_DISPATCHER::JOB_DISPATCHER()
 {
     m_reporter = &NULL_REPORTER::GetInstance();
+    m_progressReporter = nullptr;
 }
 
 
diff --git a/common/lib_table_base.cpp b/common/lib_table_base.cpp
index c96332d7d3..6f302c1610 100644
--- a/common/lib_table_base.cpp
+++ b/common/lib_table_base.cpp
@@ -344,7 +344,7 @@ bool LIB_TABLE::RemoveRow( const LIB_TABLE_ROW* aRow )
     if( !found )
     {
         // Bookkeeping got messed up...
-        for( size_t i = m_rows.size() - 1; i >= 0; --i )
+        for( int i = (int)m_rows.size() - 1; i >= 0; --i )
         {
             if( &m_rows[i] == aRow )
             {
diff --git a/common/tool/tool_action.cpp b/common/tool/tool_action.cpp
index c37e2b7e9c..d3163a61d8 100644
--- a/common/tool/tool_action.cpp
+++ b/common/tool/tool_action.cpp
@@ -73,6 +73,7 @@ TOOL_ACTION::TOOL_ACTION( const TOOL_ACTION_ARGS& aArgs ) :
         m_defaultHotKey( aArgs.m_defaultHotKey.value_or( 0 ) ),
         m_defaultHotKeyAlt( aArgs.m_defaultHotKeyAlt.value_or( 0 ) ),
         m_hotKey( aArgs.m_defaultHotKey.value_or( 0 ) ),
+        m_hotKeyAlt( 0 ),
         m_legacyName( aArgs.m_legacyName.value_or( "" ) ),
         m_label( TowxString( aArgs.m_menuText.value_or( "" ) ) ),
         m_tooltip( TowxString( aArgs.m_tooltip.value_or( "" ) ) ),
diff --git a/eeschema/dialogs/dialog_change_symbols.cpp b/eeschema/dialogs/dialog_change_symbols.cpp
index b77ef0731f..a0910c3e60 100644
--- a/eeschema/dialogs/dialog_change_symbols.cpp
+++ b/eeschema/dialogs/dialog_change_symbols.cpp
@@ -370,12 +370,13 @@ void DIALOG_CHANGE_SYMBOLS::checkAll( bool aCheck )
 
 void DIALOG_CHANGE_SYMBOLS::onOkButtonClicked( wxCommandEvent& aEvent )
 {
-    wxBusyCursor    dummy;
     SCH_EDIT_FRAME* parent = dynamic_cast<SCH_EDIT_FRAME*>( GetParent() );
-    SCH_COMMIT      commit( parent );
 
     wxCHECK( parent, /* void */ );
 
+    wxBusyCursor    dummy;
+    SCH_COMMIT      commit( parent );
+
     m_messagePanel->Clear();
     m_messagePanel->Flush( false );
 
diff --git a/eeschema/fields_data_model.h b/eeschema/fields_data_model.h
index 48101f43c7..9aed61f14d 100644
--- a/eeschema/fields_data_model.h
+++ b/eeschema/fields_data_model.h
@@ -28,6 +28,7 @@ struct DATA_MODEL_ROW
 {
     DATA_MODEL_ROW( const SCH_REFERENCE& aFirstReference, GROUP_TYPE aType )
     {
+        m_ItemNumber = 0;
         m_Refs.push_back( aFirstReference );
         m_Flag = aType;
     }
diff --git a/pcbnew/plugins/eagle/eagle_plugin.h b/pcbnew/plugins/eagle/eagle_plugin.h
index 4d3eade1c2..74489b84cd 100644
--- a/pcbnew/plugins/eagle/eagle_plugin.h
+++ b/pcbnew/plugins/eagle/eagle_plugin.h
@@ -129,7 +129,7 @@ struct ERULES
 class EAGLE_PLUGIN : public PLUGIN, public LAYER_REMAPPABLE_PLUGIN
 {
 public:
-    const wxString PluginName() const { return wxT( "Eagle" ); }
+    const wxString PluginName() const override { return wxT( "Eagle" ); }
 
     PLUGIN_FILE_DESC GetBoardFileDesc() const override
     {
diff --git a/pcbnew/plugins/geda/gpcb_plugin.cpp b/pcbnew/plugins/geda/gpcb_plugin.cpp
index a6c3f6449b..72bd130c90 100644
--- a/pcbnew/plugins/geda/gpcb_plugin.cpp
+++ b/pcbnew/plugins/geda/gpcb_plugin.cpp
@@ -842,7 +842,6 @@ FOOTPRINT* GPCB_PLUGIN::ImportFootprint( const wxString&        aFootprintPath,
 
     FILE_LINE_READER         freader( aFootprintPath );
     WHITESPACE_FILTER_READER reader( freader );
-    IO_MGR::PCB_FILE_T       file_type;
 
     reader.ReadLine();
     char* line = reader.Line();
diff --git a/pcbnew/plugins/pcad/pcad_plugin.h b/pcbnew/plugins/pcad/pcad_plugin.h
index 2e0654fd28..2427f3f9ed 100644
--- a/pcbnew/plugins/pcad/pcad_plugin.h
+++ b/pcbnew/plugins/pcad/pcad_plugin.h
@@ -38,9 +38,9 @@ public:
     PCAD_PLUGIN();
     ~PCAD_PLUGIN();
 
-    const wxString PluginName() const { return wxT( "P-Cad" ); }
+    const wxString PluginName() const override { return wxT( "P-Cad" ); }
 
-    PLUGIN_FILE_DESC GetBoardFileDesc() const
+    PLUGIN_FILE_DESC GetBoardFileDesc() const override
     {
         return PLUGIN_FILE_DESC( _HKI( "P-Cad 200x ASCII PCB files" ), { "pcb" } );
     }