diff --git a/configure.ac b/configure.ac
index 791eead..83189c3 100755
--- a/configure.ac
+++ b/configure.ac
@@ -743,6 +743,29 @@
   tutorial/rb/Makefile
 ])
 
+if test "$have_cpp" = "yes" ; then MAYBE_CPP="cpp" ; else MAYBE_CPP="" ; fi
+AC_SUBST([MAYBE_CPP])
+if test "$have_c_glib" = "yes" ; then MAYBE_C_GLIB="c_glib" ; else MAYBE_C_GLIB="" ; fi
+AC_SUBST([MAYBE_C_GLIB])
+if test "$have_java" = "yes" ; then MAYBE_JAVA="java" ; else MAYBE_JAVA="" ; fi
+AC_SUBST([MAYBE_JAVA])
+if test "$have_csharp" = "yes" ; then MAYBE_CSHARP="csharp" ; else MAYBE_CSHARP="" ; fi
+AC_SUBST([MAYBE_CSHARP])
+if test "$have_python" = "yes" ; then MAYBE_PYTHON="python" ; else MAYBE_PYTHON="" ; fi
+AC_SUBST([MAYBE_PYTHON])
+if test "$have_ruby" = "yes" ; then MAYBE_RUBY="rb" ; else MAYBE_RUBY="" ; fi
+AC_SUBST([MAYBE_RUBY])
+if test "$have_haskell" = "yes" ; then MAYBE_HASKELL="haskell" ; else MAYBE_HASKELL="" ; fi
+AC_SUBST([MAYBE_HASKELL])
+if test "$have_perl" = "yes" ; then MAYBE_PERL="perl" ; else MAYBE_PERL="" ; fi
+AC_SUBST([MAYBE_PERL])
+if test "$have_php" = "yes" ; then MAYBE_PHP="php" ; else MAYBE_PHP="" ; fi
+AC_SUBST([MAYBE_PHP])
+if test "$have_go" = "yes" ; then MAYBE_GO="go" ; else MAYBE_GO="" ; fi
+AC_SUBST([MAYBE_GO])
+if test "$have_nodejs" = "yes" ; then MAYBE_NODEJS="nodejs" ; else MAYBE_NODEJS="" ; fi
+AC_SUBST([MAYBE_NODEJS])
+
 AC_OUTPUT