diff --git a/configure.in b/configure.in
index 7df34eb..48f7700 100644
--- a/configure.in
+++ b/configure.in
@@ -201,7 +201,7 @@ dnl We biuld either with Qt4 or Qt5, but not both
 if test "${qt5_ok}" = "1" && "${qt4_ok}" = "1"; then
     AC_MSG_ERROR([Please deactivate Qt4 explicitly if you want to build with Qt5])
 fi
-AM_CONDITIONAL([BUILD_QT], [test "${qt4_ok}" = "1" || "${qt5_ok}" = "1" ])
+AM_CONDITIONAL([BUILD_QT], [test "${qt4_ok}" = "1" -o "${qt5_ok}" = "1" ])
 
 dnl Enable/disable text version
 AC_ARG_ENABLE([text],AS_HELP_STRING([--enable-text],[text interface support (default enabled)]))