diff --git a/acinclude.m4 b/acinclude.m4
index f91605b..8e19dbc 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -1333,7 +1333,7 @@ KDE_MT_LIBS=
 if test "x$kde_use_qt_mt" = "xyes"; then
   KDE_CHECK_THREADING
   if test "x$kde_use_threading" = "xyes"; then
-    CPPFLAGS="$USE_THREADS -DQT_THREAD_SUPPORT $CPPFLAGS"
+    CPPFLAGS="$USE_THREADS -DTQT_THREAD_SUPPORT $CPPFLAGS"
     KDE_MT_LDFLAGS="$USE_THREADS"
     KDE_MT_LIBS="$LIBPTHREAD"
   else
diff --git a/doc/Makefile b/doc/Makefile
index adbe291..6ba81ec 100644
--- a/doc/Makefile
+++ b/doc/Makefile
@@ -84,7 +84,7 @@ CCDEPMODE = depmode=gcc3
 CFLAGS = -std=iso9899:1990 -W -Wall -Wchar-subscripts -Wshadow -Wpointer-arith -Wmissing-prototypes -Wwrite-strings -D_XOPEN_SOURCE=500 -D_BSD_SOURCE -g3 -fno-inline   -Wformat-security -Wmissing-format-attribute
 CONF_FILES =  $(top_srcdir)/./admin/configure.in.min $(top_srcdir)/configure.in.in
 CPP = gcc -E
-CPPFLAGS =  -DQT_THREAD_SUPPORT  -D_REENTRANT
+CPPFLAGS =  -DTQT_THREAD_SUPPORT  -D_REENTRANT
 CXX = g++
 CXXCPP = g++ -E
 CXXDEPMODE = depmode=gcc3
diff --git a/doc/kmyfirewall/Makefile b/doc/kmyfirewall/Makefile
index 21c6cc8..e515418 100644
--- a/doc/kmyfirewall/Makefile
+++ b/doc/kmyfirewall/Makefile
@@ -68,7 +68,7 @@ CCDEPMODE = depmode=gcc3
 CFLAGS = -std=iso9899:1990 -W -Wall -Wchar-subscripts -Wshadow -Wpointer-arith -Wmissing-prototypes -Wwrite-strings -D_XOPEN_SOURCE=500 -D_BSD_SOURCE -g3 -fno-inline   -Wformat-security -Wmissing-format-attribute
 CONF_FILES =  $(top_srcdir)/./admin/configure.in.min $(top_srcdir)/configure.in.in
 CPP = gcc -E
-CPPFLAGS =  -DQT_THREAD_SUPPORT  -D_REENTRANT
+CPPFLAGS =  -DTQT_THREAD_SUPPORT  -D_REENTRANT
 CXX = g++
 CXXCPP = g++ -E
 CXXDEPMODE = depmode=gcc3
diff --git a/kmyfirewall/installer/openbsd/Makefile b/kmyfirewall/installer/openbsd/Makefile
index ec77d80..0d7d073 100644
--- a/kmyfirewall/installer/openbsd/Makefile
+++ b/kmyfirewall/installer/openbsd/Makefile
@@ -122,7 +122,7 @@ CCDEPMODE = depmode=gcc3
 CFLAGS = -std=iso9899:1990 -W -Wall -Wchar-subscripts -Wshadow -Wpointer-arith -Wmissing-prototypes -Wwrite-strings -D_XOPEN_SOURCE=500 -D_BSD_SOURCE -DNDEBUG -O2  -Wall -g -O2 -Wformat-security -Wmissing-format-attribute
 CONF_FILES =  $(top_srcdir)/./admin/configure.in.min $(top_srcdir)/configure.in.in
 CPP = i486-linux-gnu-gcc -E
-CPPFLAGS =  -DQT_THREAD_SUPPORT  -D_REENTRANT
+CPPFLAGS =  -DTQT_THREAD_SUPPORT  -D_REENTRANT
 CXX = i486-linux-gnu-g++
 CXXCPP = i486-linux-gnu-g++ -E
 CXXDEPMODE = depmode=gcc3