diff --git a/src/ModuleManager.h b/src/ModuleManager.h
index 2f3fbc783..1a1649c04 100644
--- a/src/ModuleManager.h
+++ b/src/ModuleManager.h
@@ -19,7 +19,6 @@
 #include <vector>
 
 #include "audacity/ModuleInterface.h"
-#include "PluginManager.h"
 
 class CommandHandler;
 
@@ -73,6 +72,7 @@ using ModuleInterfaceHandle = std::unique_ptr<
 typedef std::map<wxString, ModuleMain *> ModuleMainMap;
 typedef std::map<wxString, ModuleInterfaceHandle> ModuleMap;
 typedef std::map<ModuleInterface *, std::unique_ptr<wxDynamicLibrary>> LibraryMap;
+using PluginIDs = wxArrayString;
 
 class ModuleManager final : public ModuleManagerInterface
 {
diff --git a/src/Project.h b/src/Project.h
index 54f6f9353..dc3a2bc46 100644
--- a/src/Project.h
+++ b/src/Project.h
@@ -157,7 +157,6 @@ class ImportXMLTagHandler final : public XMLTagHandler
 };
 
 class EffectPlugs;
-typedef wxArrayString PluginIDList;
 class CommandContext;
 class CommandManager;
 class Track;
diff --git a/src/commands/GetInfoCommand.cpp b/src/commands/GetInfoCommand.cpp
index 458ff053e..38ddc6af0 100644
--- a/src/commands/GetInfoCommand.cpp
+++ b/src/commands/GetInfoCommand.cpp
@@ -41,6 +41,7 @@ This class now lists
 
 #include "../prefs/PrefsDialog.h"
 #include "../Shuttle.h"
+#include "../PluginManager.h"
 #include "../ShuttleGui.h"
 
 enum {
diff --git a/src/effects/Effect.cpp b/src/effects/Effect.cpp
index fc639d147..2ac7090f6 100644
--- a/src/effects/Effect.cpp
+++ b/src/effects/Effect.cpp
@@ -47,6 +47,7 @@ greater use in future.
 #include "../PluginManager.h"
 #include "../Prefs.h"
 #include "../Project.h"
+#include "../PluginManager.h"
 #include "../ShuttleGui.h"
 #include "../Shuttle.h"
 #include "../WaveTrack.h"
diff --git a/src/effects/EffectManager.cpp b/src/effects/EffectManager.cpp
index 26b8a722a..b15017d5f 100644
--- a/src/effects/EffectManager.cpp
+++ b/src/effects/EffectManager.cpp
@@ -35,6 +35,7 @@ effects.
 #include "../Shuttle.h"
 #include "../commands/Command.h"
 #include "../commands/CommandContext.h"
+#include "../PluginManager.h"
 
 
 /*******************************************************************************
diff --git a/src/effects/EffectManager.h b/src/effects/EffectManager.h
index 5aa3d27a4..9088f0224 100644
--- a/src/effects/EffectManager.h
+++ b/src/effects/EffectManager.h
@@ -22,7 +22,6 @@
 #include <wx/string.h>
 
 #include "audacity/EffectInterface.h"
-#include "../PluginManager.h"
 #include "Effect.h"
 
 #include <unordered_map>
diff --git a/src/menus/TrackMenus.cpp b/src/menus/TrackMenus.cpp
index 7448ef36e..d793f0a85 100644
--- a/src/menus/TrackMenus.cpp
+++ b/src/menus/TrackMenus.cpp
@@ -6,6 +6,7 @@
 
 #include "../Prefs.h"
 #include "../Project.h"
+#include "../PluginManager.h"
 #include "../ShuttleGui.h"
 #include "../TimeTrack.h"
 #include "../TrackPanel.h"