diff --git a/acinclude.m4.in b/acinclude.m4.in
index a2a33a4..443ca62 100644
--- a/acinclude.m4.in
+++ b/acinclude.m4.in
@@ -1414,7 +1414,11 @@ AC_ARG_ENABLE(
     if test $kde_qtver = 3; then
       kde_use_qt_mt=yes
     else
-      kde_use_qt_mt=no
+      if test $kde_qtver = 4; then
+        kde_use_qt_mt=yes
+      else
+        kde_use_qt_mt=no
+      fi
     fi
   ]
 )
@@ -1495,10 +1499,14 @@ dnl If we got --enable-qt-mt then adjust the Qt library name for the host.
 dnl ------------------------------------------------------------------------
 
 if test "x$kde_use_qt_mt" = "xyes"; then
-  LIBQT="-l$qtlib-mt"
-  kde_int_qt="-l$qtlib-mt"
-  if test "$kde_qtver" = "3"; then
+  if test $kde_qtver = 3; then
+    LIBQT="-l$qtlib-mt"
+    kde_int_qt="-l$qtlib-mt"
     LIBQT_GLOB="lib$qtlib-mt.*"
+  else
+    if test $kde_qtver = 4; then
+      LIBQT="-l$qtlib"
+    fi
   fi
   USING_QT_MT="using -mt"
 else