diff --git a/include/audacity/ConfigInterface.h b/include/audacity/ConfigInterface.h
index 81cfdcf13..8eb7b37a6 100644
--- a/include/audacity/ConfigInterface.h
+++ b/include/audacity/ConfigInterface.h
@@ -44,7 +44,7 @@
 
 #include "audacity/Types.h"
 
-class ConfigClientInterface
+class AUDACITY_DLL_API ConfigClientInterface
 {
 public:
    virtual ~ConfigClientInterface() {};
diff --git a/include/audacity/EffectInterface.h b/include/audacity/EffectInterface.h
index 6e81a9283..239f91f4d 100644
--- a/include/audacity/EffectInterface.h
+++ b/include/audacity/EffectInterface.h
@@ -56,7 +56,7 @@ typedef enum EffectType
    EffectTypeAnalyze
 } EffectType;
 
-class EffectIdentInterface : public IdentInterface
+class AUDACITY_DLL_API EffectIdentInterface : public IdentInterface
 {
 public:
    virtual ~EffectIdentInterface() {};
@@ -80,8 +80,9 @@ public:
    virtual bool IsRealtimeCapable() = 0;
 };
 
-class EffectHostInterface : public EffectIdentInterface,
-                            public ConfigClientInterface
+class AUDACITY_DLL_API EffectHostInterface : 
+   public EffectIdentInterface,
+   public ConfigClientInterface
 {
 public:
    virtual ~EffectHostInterface() {};
diff --git a/include/audacity/IdentInterface.h b/include/audacity/IdentInterface.h
index 7982b71eb..6894d08bd 100644
--- a/include/audacity/IdentInterface.h
+++ b/include/audacity/IdentInterface.h
@@ -44,7 +44,7 @@
 
 #include "audacity/Types.h"
 
-class IdentInterface
+class AUDACITY_DLL_API IdentInterface
 {
 public:
    virtual ~IdentInterface() {};
diff --git a/include/audacity/PluginInterface.h b/include/audacity/PluginInterface.h
index 3b126c259..d9275ff7d 100644
--- a/include/audacity/PluginInterface.h
+++ b/include/audacity/PluginInterface.h
@@ -48,8 +48,8 @@
 #include "audacity/IdentInterface.h"
 #include "audacity/ImporterInterface.h"
 
-class IdentInterface;
-class EffectIdentInterface;
+class AUDACITY_DLL_API IdentInterface;
+class AUDACITY_DLL_API EffectIdentInterface;
 class PluginManagerInterface
 {
 public:
diff --git a/src/effects/EffectCategory.cpp b/src/effects/EffectCategory.cpp
index 0e2277f1b..d9de6a5ca 100644
--- a/src/effects/EffectCategory.cpp
+++ b/src/effects/EffectCategory.cpp
@@ -9,6 +9,7 @@
 
 **********************************************************************/
 
+#include "../Audacity.h"
 
 #include "Effect.h"
 #include "EffectCategory.h"
diff --git a/src/effects/EffectManager.cpp b/src/effects/EffectManager.cpp
index 746e61873..8600abdf5 100644
--- a/src/effects/EffectManager.cpp
+++ b/src/effects/EffectManager.cpp
@@ -9,6 +9,8 @@
 
 **********************************************************************/
 
+#include "../Audacity.h"
+
 #include <wx/msgdlg.h>
 #include <wx/stopwatch.h>
 #include <wx/tokenzr.h>
diff --git a/src/effects/EffectRack.cpp b/src/effects/EffectRack.cpp
index ee1e27d8f..262bef2f7 100644
--- a/src/effects/EffectRack.cpp
+++ b/src/effects/EffectRack.cpp
@@ -11,6 +11,7 @@
 
 **********************************************************************/
 
+#include "../Audacity.h"
 #include "../Experimental.h"
 
 #if defined(EXPERIMENTAL_EFFECTS_RACK)
diff --git a/src/effects/Noise.cpp b/src/effects/Noise.cpp
index 8cc10eefe..9a132beb7 100644
--- a/src/effects/Noise.cpp
+++ b/src/effects/Noise.cpp
@@ -13,13 +13,13 @@
 
 *//*******************************************************************/
 
-#include "Noise.h"
 #include "../Audacity.h"
 #include "../Project.h"
 #include "../Prefs.h"
 #include "../ShuttleGui.h"
 #include "../WaveTrack.h"
 #include "../widgets/NumericTextCtrl.h"
+#include "Noise.h"
 
 #include <math.h>
 
diff --git a/src/effects/Reverb.cpp b/src/effects/Reverb.cpp
index 504693933..649705550 100644
--- a/src/effects/Reverb.cpp
+++ b/src/effects/Reverb.cpp
@@ -19,6 +19,7 @@
 
 *//*******************************************************************/
 
+#include "../Audacity.h"
 #include "Reverb.h"
 #include "Reverb_libSoX.h"
 #include "../Prefs.h"
diff --git a/src/effects/vamp/LoadVamp.cpp b/src/effects/vamp/LoadVamp.cpp
index bb27a3bb9..09877aee6 100644
--- a/src/effects/vamp/LoadVamp.cpp
+++ b/src/effects/vamp/LoadVamp.cpp
@@ -8,6 +8,7 @@
 
 **********************************************************************/
 
+#include "../../Audacity.h"
 #include "../EffectManager.h"
 #include "VampEffect.h"
 #include "LoadVamp.h"
diff --git a/src/effects/vamp/VampEffect.cpp b/src/effects/vamp/VampEffect.cpp
index b9bad2ccd..ffe5af462 100644
--- a/src/effects/vamp/VampEffect.cpp
+++ b/src/effects/vamp/VampEffect.cpp
@@ -11,6 +11,7 @@
 
 **********************************************************************/
 
+#include "../../Audacity.h"
 #include "VampEffect.h"
 
 #include <vamp-hostsdk/Plugin.h>