diff --git a/src/AdornedRulerPanel.h b/src/AdornedRulerPanel.h
index 389b4d26d..6b0546aed 100644
--- a/src/AdornedRulerPanel.h
+++ b/src/AdornedRulerPanel.h
@@ -16,7 +16,6 @@
 
 #include "MemoryX.h"
 #include <wx/bitmap.h>
-#include <wx/dc.h>
 #include <wx/dcmemory.h>
 
 class ViewInfo;
diff --git a/src/Envelope.h b/src/Envelope.h
index ce64ddac0..15e7f0aa7 100644
--- a/src/Envelope.h
+++ b/src/Envelope.h
@@ -22,7 +22,6 @@
 #include "Internat.h"
 
 class wxRect;
-class wxDC;
 class wxMouseEvent;
 class wxTextFile;
 
diff --git a/src/FreqWindow.h b/src/FreqWindow.h
index e6b98e3a8..714026260 100644
--- a/src/FreqWindow.h
+++ b/src/FreqWindow.h
@@ -21,13 +21,12 @@
 #include <wx/pen.h>
 #include <wx/font.h> // member variable
 #include <wx/scrolbar.h>
-#include <wx/statusbr.h>
+#include <wx/statusbr.h> // to inherit
 #include <wx/utils.h>
 #include "SampleFormat.h"
 #include "widgets/wxPanelWrapper.h"
 
 class wxSlider;
-class wxStatusBar;
 class wxTextCtrl;
 class wxButton;
 class wxCheckBox;
diff --git a/src/TimeTrack.h b/src/TimeTrack.h
index e9349ddfb..d81ccdfbd 100644
--- a/src/TimeTrack.h
+++ b/src/TimeTrack.h
@@ -18,7 +18,6 @@
 #include <algorithm>
 
 class wxRect;
-class wxDC;
 class Envelope;
 class Ruler;
 class ZoomInfo;
diff --git a/src/commands/AudacityCommand.h b/src/commands/AudacityCommand.h
index 3d001c606..36e995029 100644
--- a/src/commands/AudacityCommand.h
+++ b/src/commands/AudacityCommand.h
@@ -20,7 +20,6 @@
 #include <wx/defs.h>
 #include <wx/dynarray.h>
 #include <wx/intl.h>
-#include <wx/tglbtn.h>
 
 class wxListBox;
 class wxWindow;
diff --git a/src/commands/CommandTargets.h b/src/commands/CommandTargets.h
index bfb24919c..d15c1b86b 100644
--- a/src/commands/CommandTargets.h
+++ b/src/commands/CommandTargets.h
@@ -57,12 +57,13 @@ and sends it to that message target.
 
 #include "../MemoryX.h"
 #include <vector>
-#include <wx/statusbr.h>
 //#include "../src/Project.h"
 #include "../widgets/ProgressDialog.h"
 #include "../commands/ResponseQueue.h"
 #include "../widgets/ErrorDialog.h"
 
+class wxStatusBar;
+
 /// Interface for objects that can receive command progress information
 class CommandProgressTarget /* not final */
 {
diff --git a/src/effects/Effect.h b/src/effects/Effect.h
index 399c3496b..62ca5756a 100644
--- a/src/effects/Effect.h
+++ b/src/effects/Effect.h
@@ -22,7 +22,6 @@
 #include "../MemoryX.h"
 #include <wx/defs.h>
 #include <wx/intl.h>
-#include <wx/tglbtn.h>
 
 class wxButton;
 class wxCheckBox;
diff --git a/src/effects/nyquist/Nyquist.cpp b/src/effects/nyquist/Nyquist.cpp
index 6f3fc40f2..00590c746 100644
--- a/src/effects/nyquist/Nyquist.cpp
+++ b/src/effects/nyquist/Nyquist.cpp
@@ -45,6 +45,7 @@ effects from this one class.
 #include <wx/sstream.h>
 #include <wx/stattext.h>
 #include <wx/textdlg.h>
+#include <wx/tokenzr.h>
 #include <wx/txtstrm.h>
 #include <wx/valgen.h>
 #include <wx/wfstream.h>
diff --git a/src/effects/nyquist/Nyquist.h b/src/effects/nyquist/Nyquist.h
index b7dd59fb3..95f5d706d 100644
--- a/src/effects/nyquist/Nyquist.h
+++ b/src/effects/nyquist/Nyquist.h
@@ -15,7 +15,6 @@
 #include <wx/dialog.h>
 #include <wx/intl.h>
 #include <wx/textbuf.h>
-#include <wx/tokenzr.h>
 
 #include "../Effect.h"
 
diff --git a/src/export/Export.cpp b/src/export/Export.cpp
index bc50a1eff..4eb98043f 100644
--- a/src/export/Export.cpp
+++ b/src/export/Export.cpp
@@ -35,6 +35,7 @@
 #include <wx/filectrl.h>
 #include <wx/filename.h>
 #include <wx/progdlg.h>
+#include <wx/simplebook.h>
 #include <wx/sizer.h>
 #include <wx/slider.h>
 #include <wx/statbox.h>
diff --git a/src/export/Export.h b/src/export/Export.h
index 8b88892f4..1a735e7b7 100644
--- a/src/export/Export.h
+++ b/src/export/Export.h
@@ -14,7 +14,6 @@
 #include "../MemoryX.h"
 #include <vector>
 #include <wx/dialog.h>
-#include <wx/simplebook.h>
 #include "../Tags.h"
 #include "../SampleFormat.h"
 #include "../widgets/wxPanelWrapper.h"
@@ -24,6 +23,7 @@ class wxFileName;
 class FileDialogWrapper;
 class wxFileCtrlEvent;
 class wxMemoryDC;
+class wxSimplebook;
 class wxStaticText;
 class AudacityProject;
 class DirManager;
diff --git a/src/export/ExportMultiple.cpp b/src/export/ExportMultiple.cpp
index 6be0bd111..373cc5ac6 100644
--- a/src/export/ExportMultiple.cpp
+++ b/src/export/ExportMultiple.cpp
@@ -30,6 +30,7 @@
 #include <wx/filename.h>
 #include <wx/intl.h>
 #include <wx/radiobut.h>
+#include <wx/simplebook.h>
 #include <wx/sizer.h>
 #include <wx/statbox.h>
 #include <wx/stattext.h>
diff --git a/src/export/ExportMultiple.h b/src/export/ExportMultiple.h
index 32917e8e2..e331c95d7 100644
--- a/src/export/ExportMultiple.h
+++ b/src/export/ExportMultiple.h
@@ -13,7 +13,6 @@
 
 #include <wx/dialog.h>
 #include <wx/listctrl.h>
-#include <wx/simplebook.h>
 
 #include "Export.h"
 #include "../Tags.h"       // we need to know about the Tags class for metadata
@@ -23,6 +22,7 @@ class wxButton;
 class wxCheckBox;
 class wxChoice;
 class wxRadioButton;
+class wxSimplebook;
 class wxStaticText;
 class wxTextCtrl;
 
diff --git a/src/import/Import.h b/src/import/Import.h
index 697c648c8..a443afafa 100644
--- a/src/import/Import.h
+++ b/src/import/Import.h
@@ -16,7 +16,7 @@
 #include "audacity/Types.h"
 #include <vector>
 #include <wx/listbox.h>
-#include <wx/tokenzr.h>
+#include <wx/tokenzr.h> // for enum wxStringTokenizerMode
 
 #include "../widgets/wxPanelWrapper.h"
 
diff --git a/src/widgets/Grabber.h b/src/widgets/Grabber.h
index 51792f4b6..2b00f922f 100644
--- a/src/widgets/Grabber.h
+++ b/src/widgets/Grabber.h
@@ -32,7 +32,6 @@ flicker-free use.
 #include "../Audacity.h"
 
 #include <wx/defs.h>
-#include <wx/dc.h>
 #include <wx/gdicmn.h>
 #include <wx/statbmp.h>
 
diff --git a/src/widgets/ImageRoll.h b/src/widgets/ImageRoll.h
index 688666546..529a6e52b 100644
--- a/src/widgets/ImageRoll.h
+++ b/src/widgets/ImageRoll.h
@@ -13,7 +13,6 @@
 #define __AUDACITY_IMAGE_ROLL__
 
 #include <vector>
-#include <wx/dc.h>
 #include <wx/dcclient.h>
 #include <wx/defs.h>
 #include <wx/version.h>