diff --git a/acinclude.m4.in b/acinclude.m4.in
index 9189858..6f39a26 100644
--- a/acinclude.m4.in
+++ b/acinclude.m4.in
@@ -1083,11 +1083,12 @@ AC_DEFUN([KDE_USE_TQT],
 [
   kde_tqtver=0
   kde_tqtsubver=0
-  
+
+  KDE_PKG_CHECK_MODULES(TQt, tqt)
   AC_LANG_SAVE
   AC_LANG_CPLUSPLUS
   ac_cxxflags_safe="$CXXFLAGS"
-  CXXFLAGS="$CXXFLAGS -I/usr/include/tqt -I/usr/include/tqt3"
+  CXXFLAGS="$CXXFLAGS $TQt_CFLAGS"
   AC_TRY_COMPILE([
   #include <tqt.h>
   ], ,