diff --git a/ConfigureChecks.cmake b/ConfigureChecks.cmake
index c0bcd225..6789c4c0 100644
--- a/ConfigureChecks.cmake
+++ b/ConfigureChecks.cmake
@@ -11,6 +11,9 @@
 
 tde_setup_architecture_flags( )
 
+include(TestBigEndian)
+test_big_endian(WORDS_BIGENDIAN)
+
 ##### check for gcc visibility support #########
 # FIXME
 # This should check for [T]Qt3 visibility support
@@ -25,6 +28,10 @@ if( WITH_GCC_VISIBILITY )
 endif( )
 
 
+if( BUILD_KMAIL )
+  check_include_file( "byteswap.h" HAVE_BYTESWAP_H )
+endif( )
+
 if( BUILD_LIBTDEPIM OR BUILD_KMAIL )
   option( TDEPIM_NEW_DISTRLISTS "Define if you want to use the new distribution lists" ON )
 endif( )
diff --git a/config.h.cmake b/config.h.cmake
index 206a8123..eb51aa52 100644
--- a/config.h.cmake
+++ b/config.h.cmake
@@ -1,3 +1,8 @@
+
+/* Define WORDS_BIGENDIAN to 1 if your processor stores words with the most
+   significant byte first (like Motorola and SPARC, unlike Intel). */
+#cmakedefine WORDS_BIGENDIAN @WORDS_BIGENDIAN@
+
 // libkcal
 #cmakedefine USE_LIBICAL_0_46 1
 
@@ -33,6 +38,7 @@
 #cmakedefine HAVE_LIBSASL2 1
 
 // kmail
+#cmakedefine HAVE_BYTESWAP_H 1
 #cmakedefine HAVE_STLNAMESPACE 1
 #cmakedefine STD_NAMESPACE_PREFIX @STD_NAMESPACE_PREFIX@
 
diff --git a/ktnef/gui/CMakeLists.txt b/ktnef/gui/CMakeLists.txt
index 57527c9a..a89cedbf 100644
--- a/ktnef/gui/CMakeLists.txt
+++ b/ktnef/gui/CMakeLists.txt
@@ -15,6 +15,7 @@ include_directories(
   ${CMAKE_CURRENT_BINARY_DIR}
   ${CMAKE_SOURCE_DIR}/ktnef
   ${CMAKE_SOURCE_DIR}/libtdepim
+  ${CMAKE_BINARY_DIR}
   ${TDE_INCLUDE_DIR}
   ${TQT_INCLUDE_DIRS}
 )
diff --git a/ktnef/gui/qwmf.cpp b/ktnef/gui/qwmf.cpp
index 37eaa170..e4baf41d 100644
--- a/ktnef/gui/qwmf.cpp
+++ b/ktnef/gui/qwmf.cpp
@@ -17,6 +17,8 @@
  * MA  02110-1301, USA.
  */
 
+#include <config.h>
+
 #include <math.h>
 #include <assert.h>
 #include <tqfileinfo.h>