diff --git a/src/BatchCommands.cpp b/src/BatchCommands.cpp
index e748cf268..e5a8ac7fb 100644
--- a/src/BatchCommands.cpp
+++ b/src/BatchCommands.cpp
@@ -34,6 +34,7 @@ processing.  See also MacrosWindow and ApplyMacroDialog.
 #include "PluginManager.h"
 #include "Prefs.h"
 #include "Shuttle.h"
+#include "Track.h"
 #include "export/ExportFLAC.h"
 #include "export/ExportMP3.h"
 #include "export/ExportOGG.h"
diff --git a/src/effects/EffectManager.cpp b/src/effects/EffectManager.cpp
index 817b0ae60..881ab814f 100644
--- a/src/effects/EffectManager.cpp
+++ b/src/effects/EffectManager.cpp
@@ -23,6 +23,8 @@ effects.
 
 #include "../Experimental.h"
 
+#include "Effect.h"
+
 #include <algorithm>
 #include <wx/stopwatch.h>
 #include <wx/tokenzr.h>
diff --git a/src/effects/EffectManager.h b/src/effects/EffectManager.h
index 8c99a0f6d..eea9e3e75 100644
--- a/src/effects/EffectManager.h
+++ b/src/effects/EffectManager.h
@@ -14,16 +14,23 @@
 
 #include "../Experimental.h"
 
+#include <memory>
 #include <vector>
 
-#include "audacity/EffectInterface.h"
-#include "Effect.h"
-
 #include <unordered_map>
+#include <wx/thread.h>
+#include "audacity/Types.h"
 
 class AudacityCommand;
 class CommandContext;
 class CommandMessageTarget;
+class ComponentInterfaceSymbol;
+class Effect;
+class TrackFactory;
+class TrackList;
+class SelectedRegion;
+class wxString;
+typedef wxString PluginID;
 
 using EffectArray = std::vector <Effect*> ;
 using EffectMap = std::unordered_map<wxString, Effect *>;
diff --git a/src/effects/EffectRack.cpp b/src/effects/EffectRack.cpp
index 7be9a7599..16cbfe207 100644
--- a/src/effects/EffectRack.cpp
+++ b/src/effects/EffectRack.cpp
@@ -16,6 +16,9 @@
 
 #include "../Experimental.h"
 
+#include "Effect.h"
+#include "EffectManager.h"
+
 #if defined(EXPERIMENTAL_EFFECTS_RACK)
 
 #include "../UndoManager.h"
@@ -39,6 +42,7 @@
 #include "../Prefs.h"
 #include "../Project.h"
 #include "../ProjectHistory.h"
+#include "../widgets/wxPanelWrapper.h"
 
 #include "../../images/EffectRack/EffectRack.h"
 
diff --git a/src/effects/EffectRack.h b/src/effects/EffectRack.h
index fb47a3e4c..5fcc2c987 100644
--- a/src/effects/EffectRack.h
+++ b/src/effects/EffectRack.h
@@ -18,16 +18,19 @@
 
 #if defined(EXPERIMENTAL_EFFECTS_RACK)
 
+#include <vector>
+
 #include <wx/defs.h>
 #include <wx/frame.h> // to inherit
 #include <wx/timer.h> // member variable
 
-#include "EffectManager.h"
-
 class wxFlexGridSizer;
 class wxPanel;
 class wxStaticText;
 
+class Effect;
+using EffectArray = std::vector<Effect*>;
+
 class EffectRack final : public wxFrame
 {
 public:
diff --git a/src/effects/lv2/LoadLV2.cpp b/src/effects/lv2/LoadLV2.cpp
index 6dcc4be5b..6fcaef762 100644
--- a/src/effects/lv2/LoadLV2.cpp
+++ b/src/effects/lv2/LoadLV2.cpp
@@ -30,6 +30,7 @@ Functions that find and load all LV2 plugins on the system.
 #include <wx/string.h>
 
 #include "../EffectManager.h"
+#include "../../Internat.h"
 
 #include "LV2Effect.h"
 #include "lv2/lv2plug.in/ns/ext/event/event.h"