diff --git a/korundum/rubylib/korundum/configure.in.in b/korundum/rubylib/korundum/configure.in.in
index e0d581b1..e4ab2fdd 100644
--- a/korundum/rubylib/korundum/configure.in.in
+++ b/korundum/rubylib/korundum/configure.in.in
@@ -16,6 +16,7 @@ else
       RUBY_SITEDIR=`ruby -r rbconfig -e 'printf("%s",RbConfig::CONFIG@<:@"sitelibdir"@:>@)'`
       RUBY_RUBYLIBDIR=`ruby -r rbconfig -e 'printf("%s",RbConfig::CONFIG@<:@"rubylibdir"@:>@)'`
       RUBY_CFLAGS=`$PKGCONFIG ruby --cflags`
+      AC_DEFINE_UNQUOTED(HAVE_RUBY_1_9, 1, [Defines if your system has Ruby 1.9.x])
     fi
   fi
   if test -z "$RUBY_VERSION"; then
diff --git a/qtruby/rubylib/qtruby/configure.in.in b/qtruby/rubylib/qtruby/configure.in.in
index a875b2f8..7ad0e4d4 100644
--- a/qtruby/rubylib/qtruby/configure.in.in
+++ b/qtruby/rubylib/qtruby/configure.in.in
@@ -18,6 +18,7 @@ else
       RUBY_LIBDIR=`$RUBY -r rbconfig -e 'printf("%s",RbConfig::CONFIG@<:@"libdir"@:>@)'`
       RUBY_LIBRUBYARG=`$RUBY -r rbconfig -e 'printf("%s",RbConfig::CONFIG@<:@"LIBRUBYARG_SHARED"@:>@)'`
       RUBY_CFLAGS=`$PKGCONFIG ruby --cflags`
+      AC_DEFINE_UNQUOTED(HAVE_RUBY_1_9, 1, [Defines if your system has Ruby 1.9.x])
     fi
   fi
   if test -z "$RUBY_VERSION"; then