diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -4,6 +4,9 @@
 #add_definitions( -DQT_NO_CAST_FROM_ASCII )
 #add_definitions( -DQT_NO_CAST_TO_ASCII )
 
+if(BUILD_TESTING)
+   add_definitions(-DBUILD_TESTING)
+endif(BUILD_TESTING)
 
 set(libmailcommon_filter_SRCS
   filter/kmfilteraccountlist.cpp
diff --git a/src/filter/autotests/CMakeLists.txt b/src/filter/autotests/CMakeLists.txt
--- a/src/filter/autotests/CMakeLists.txt
+++ b/src/filter/autotests/CMakeLists.txt
@@ -112,7 +112,6 @@
     ../filteractions/filteractionplaysound.cpp
     ../soundtestwidget.cpp
     ../dialog/filteractionmissingsoundurldialog.cpp
-    ../kmfilteraccountlist.cpp
     ${filter_common_SRCS}
 )
 
@@ -167,7 +166,6 @@
     ../filteractions/filteractionwithaddress.cpp
     ../filteractions/filteractionwithstring.cpp
     ../dialog/filteractionmissingtemplatedialog.cpp
-    ../kmfilteraccountlist.cpp
     ${filter_common_SRCS}
 )
 
@@ -210,7 +208,6 @@
     filteractionsettransporttest.cpp
     ../filteractions/filteractionsettransport.cpp
     ../dialog/filteractionmissingtransportdialog.cpp
-    ../kmfilteraccountlist.cpp
     ${filter_common_SRCS}
 )
 
@@ -243,7 +240,6 @@
 add_mailcommon_filter_test(filteractionmissingaccountdialogtest
     filteractionmissingaccountdialogtest.cpp
     ../dialog/filteractionmissingaccountdialog.cpp
-    ../../filter/kmfilteraccountlist.cpp
     )
 
 add_mailcommon_filter_test(filteractionmissingtagdialogtest
diff --git a/src/filter/kmfilteraccountlist.h b/src/filter/kmfilteraccountlist.h
--- a/src/filter/kmfilteraccountlist.h
+++ b/src/filter/kmfilteraccountlist.h
@@ -17,11 +17,15 @@
 
 #ifndef KMFILTERACCOUNTLIST_H
 #define KMFILTERACCOUNTLIST_H
+
 #include <QTreeWidget>
+
+#include "mailcommon_private_export.h"
+
 namespace MailCommon
 {
 class MailFilter;
-class KMFilterAccountList : public QTreeWidget
+class MAILCOMMON_TESTS_EXPORT KMFilterAccountList : public QTreeWidget
 {
     Q_OBJECT
 public:
diff --git a/src/mailcommon_private_export.h b/src/mailcommon_private_export.h
new file mode 100644
--- /dev/null
+++ b/src/mailcommon_private_export.h
@@ -0,0 +1,35 @@
+/*  This file is part of the KDE project
+    Copyright (C) 2007 David Faure <faure@kde.org>
+
+    This library is free software; you can redistribute it and/or
+    modify it under the terms of the GNU Library General Public
+    License as published by the Free Software Foundation; either
+    version 2 of the License, or (at your option) any later version.
+
+    This library is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+    Library General Public License for more details.
+
+    You should have received a copy of the GNU Library General Public License
+    along with this library; see the file COPYING.LIB.  If not, write to
+    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+    Boston, MA 02110-1301, USA.
+*/
+
+#ifndef MAILCOMMONPRIVATE_EXPORT_H
+#define MAILCOMMONPRIVATE_EXPORT_H
+
+#include "mailcommon_export.h"
+
+/* Classes which are exported only for unit tests */
+#ifdef BUILD_TESTING
+# ifndef MAILCOMMON_TESTS_EXPORT
+#  define MAILCOMMON_TESTS_EXPORT MAILCOMMON_EXPORT
+# endif
+#else /* not compiling tests */
+# define MAILCOMMON_TESTS_EXPORT
+#endif
+
+#endif
+