--- din-5.2.1/configure.ac
+++ din-5.2.1/configure.ac
@@ -3,7 +3,7 @@
 AC_CONFIG_SRCDIR([configure.ac])
 AC_PROG_CXX
 AC_CHECK_HEADERS([GL/gl.h],AC_MSG_NOTICE([+++ Found OpenGL +++]),[AC_MSG_ERROR([!!! Please install OpenGL !!!])])
-AC_CHECK_HEADERS([tcl.h] [tcl8.5/tcl.h],AC_MSG_NOTICE([+++ Found Tcl 8.5 +++]),[AC_MSG_WARN([!!! Is Tcl 8.5 installed? !!!])])
+AC_CHECK_HEADERS([tcl.h], AC_MSG_NOTICE([+++ Found Tcl +++]),[AC_MSG_ERROR([!!! Please install Tcl !!!])])
 AC_CHECK_HEADERS([libircclient/libircclient.h],,[AC_MSG_ERROR([!!! Please install libircclient !!!])])
 PKG_CHECK_MODULES([liblo], [liblo])
 PKG_CHECK_MODULES([jack], [jack])