diff --git a/lib/kross/configure.in.in b/lib/kross/configure.in.in
index c9acf48b1..67e9aaf57 100644
--- a/lib/kross/configure.in.in
+++ b/lib/kross/configure.in.in
@@ -40,11 +40,14 @@ if test "x$compile_kross" = "xyes" ; then
     fi
 
     RUBY_SERIES="$RUBY_MAJOR$RUBY_MINOR"
+    RUBY_VERSION_DEFS=""
     if test "$RUBY_SERIES" -ge "19"; then
        AC_DEFINE_UNQUOTED(HAVE_RUBY_1_9, 1, [Defines if your system has Ruby 1.9.x])
+       RUBY_VERSION_DEFS="${RUBY_VERSION_DEFS} -DHAVE_RUBY_1_9"
     fi
     if test "$RUBY_SERIES" -ge "30"; then
        AC_DEFINE_UNQUOTED(HAVE_RUBY_3, 1, [Defines if your system has Ruby 3.x])
+       RUBY_VERSION_DEFS="${RUBY_VERSION_DEFS} -DHAVE_RUBY_3"
     fi
 
     if test `${RUBY_EXECUTABLE} -r rbconfig -e "puts RbConfig::CONFIG.key?(%q(rubyhdrdir))"` = "true"; then
@@ -85,6 +88,7 @@ if test "x$compile_kross" = "xyes" ; then
     AC_SUBST(RUBY_LIBRUBYARG)
     AC_SUBST(RUBY_CFLAGS)
     AC_SUBST(RUBY_ENABLESHARED)
+    AC_SUBST(RUBY_VERSION_DEFS)
 
 
     AC_MSG_CHECKING(Ruby shared library)
diff --git a/lib/kross/ruby/Makefile.am b/lib/kross/ruby/Makefile.am
index 25872fddf..1dba42439 100644
--- a/lib/kross/ruby/Makefile.am
+++ b/lib/kross/ruby/Makefile.am
@@ -2,7 +2,7 @@ include $(top_srcdir)/lib/kross/Makefile.global
 
 CXXFLAGS += $(USE_EXCEPTIONS)
 
-INCLUDES = -I$(top_srcdir)/lib/kross -I$(RUBY_INCLUDEDIR) $(RUBY_CFLAGS) $(all_includes)
+INCLUDES = -I$(top_srcdir)/lib/kross -I$(RUBY_INCLUDEDIR) $(RUBY_CFLAGS) $(RUBY_VERSION_DEFS) $(all_includes)
 METASOURCES = AUTO
 kde_module_LTLIBRARIES = krossruby.la
 
diff --git a/lib/kross/ruby/rubyinterpreter.cpp b/lib/kross/ruby/rubyinterpreter.cpp
index 3504ca7c4..b453a238f 100644
--- a/lib/kross/ruby/rubyinterpreter.cpp
+++ b/lib/kross/ruby/rubyinterpreter.cpp
@@ -17,7 +17,6 @@
  * Boston, MA 02110-1301, USA.
  ***************************************************************************/
 
-#include "config.h"
 #include "rubyinterpreter.h"
 
 #include <map>
diff --git a/lib/kross/ruby/rubywrapper.c b/lib/kross/ruby/rubywrapper.c
index a25b1b282..5fafd6b80 100644
--- a/lib/kross/ruby/rubywrapper.c
+++ b/lib/kross/ruby/rubywrapper.c
@@ -17,7 +17,6 @@
  * Boston, MA 02110-1301, USA.
  ***************************************************************************/
 
-#include "config.h"
 #include "ruby.h"
 
 void kross_rb_set_safe_level(int safelevel) {