diff --git a/Doxyfile.global b/Doxyfile.global
index 520ba3e..6c30c56 100755
--- a/Doxyfile.global
+++ b/Doxyfile.global
@@ -1280,7 +1280,7 @@ INCLUDE_FILE_PATTERNS  =
 # undefined via #undef or recursively expanded use the := operator
 # instead of the = operator.
 
-PREDEFINED             = QT_VERSION=320 \
+PREDEFINED             = TQT_VERSION=320 \
                          __cplusplus \
                          Q_WS_X11
 
diff --git a/acinclude.m4.in b/acinclude.m4.in
index ede5762..1e6261a 100644
--- a/acinclude.m4.in
+++ b/acinclude.m4.in
@@ -1174,7 +1174,7 @@ EOF
 
 if test $kde_qtsubver -gt 0; then
 cat >> conftest.$ac_ext <<EOF
-#if QT_VERSION < 210
+#if TQT_VERSION < 210
 #error 1
 #endif
 EOF
@@ -1340,31 +1340,31 @@ fi
 if test -z "$3"; then
    if test $kde_qtver = 4; then
      if test $kde_qtsubver -gt 0; then
-       kde_qt_verstring="QT_VERSION >= 0x04@VER@00 && QT_VERSION < 0x050000"
+       kde_qt_verstring="TQT_VERSION >= 0x04@VER@00 && TQT_VERSION < 0x050000"
        qtsubver=`echo "00$kde_qtsubver" | sed -e 's,.*\(..\)$,\1,'`
        kde_qt_verstring=`echo $kde_qt_verstring | sed -e "s,@VER@,$qtsubver,"`
      else
-       kde_qt_verstring="QT_VERSION >= 400 && QT_VERSION < 0x050000"
+       kde_qt_verstring="TQT_VERSION >= 400 && TQT_VERSION < 0x050000"
      fi
    fi
    if test $kde_qtver = 3; then
      if test $kde_qtsubver -gt 0; then
-       kde_qt_verstring="QT_VERSION >= 0x03@VER@00 && QT_VERSION < 0x040000"
+       kde_qt_verstring="TQT_VERSION >= 0x03@VER@00 && TQT_VERSION < 0x040000"
        qtsubver=`echo "00$kde_qtsubver" | sed -e 's,.*\(..\)$,\1,'`
        kde_qt_verstring=`echo $kde_qt_verstring | sed -e "s,@VER@,$qtsubver,"`
      else
-       kde_qt_verstring="QT_VERSION >= 300 && QT_VERSION < 0x040000"
+       kde_qt_verstring="TQT_VERSION >= 300 && TQT_VERSION < 0x040000"
      fi
    fi
    if test $kde_qtver = 2; then
      if test $kde_qtsubver -gt 0; then
-       kde_qt_verstring="QT_VERSION >= 222"
+       kde_qt_verstring="TQT_VERSION >= 222"
      else
-       kde_qt_verstring="QT_VERSION >= 200"
+       kde_qt_verstring="TQT_VERSION >= 200"
      fi
    fi
    if test $kde_qtver = 1; then
-    kde_qt_verstring="QT_VERSION >= 142 && QT_VERSION < 200"
+    kde_qt_verstring="TQT_VERSION >= 142 && TQT_VERSION < 200"
    fi
 else
    kde_qt_verstring="$3"