diff --git a/configure.in.in b/configure.in.in
index 9bbda0345..9f1b7bea1 100644
--- a/configure.in.in
+++ b/configure.in.in
@@ -223,8 +223,8 @@ if test "$kde_cv_mtab_file" != "no"; then
     AC_DEFINE_UNQUOTED(MTAB_FILE, "$kde_cv_mtab_file", [Define the file for mount entries])
 fi
 
-if test -n "$qt_includes"; then
-  QNAMESPACE_H="$qt_includes/qnamespace.h"
+if test -n "$tqt_includes"; then
+  QNAMESPACE_H="$tqt_includes/qnamespace.h"
 fi
 AC_SUBST(QNAMESPACE_H)