diff --git a/configure.in b/configure.in
index c6a358c..abb7cec 100644
--- a/configure.in
+++ b/configure.in
@@ -110,7 +110,7 @@ AC_ARG_ENABLE(pkcs11-download,
   ])
 dnl problem in libs: -Wshadow -Wcast-qual
 dnl auto.hpp: -Wno-ctor-dtor-privacy (removed)
-AC_CHECK_HEADER([pkcs11.h], [], [AC_MSG_ERROR([Header pkcs11.h is required])])
+dnl AC_CHECK_HEADER([pkcs11.h], [], [AC_MSG_ERROR([Header pkcs11.h is required])])
 AC_CHECK_HEADER([wintypes.h], [], [AC_MSG_ERROR([Header wintypes.h is required])])
 PKG_CHECK_MODULES([QT_GUI], [Qt5Core Qt5Gui Qt5Widgets],
    [AC_DEFINE([HAVE_QTGUI])