diff --git a/src/configure.ac b/src/configure.ac
index d440a46..a098da8 100644
--- a/src/configure.ac
+++ b/src/configure.ac
@@ -1966,7 +1966,7 @@
 	    libruby_soname=`$vi_cv_path_ruby -r rbconfig -e "puts $ruby_rbconfig::CONFIG[['LIBRUBY_SO']]"`
 	  fi
 	  AC_DEFINE(DYNAMIC_RUBY)
-	  RUBY_CFLAGS="-DDYNAMIC_RUBY_DLL=\\\"$libruby_soname\\\" -DDYNAMIC_RUBY_VER=$rubyversion $RUBY_CFLAGS"
+	  RUBY_CFLAGS="-DDYNAMIC_RUBY_DLL=\\\"$libruby_soname\\\" $RUBY_CFLAGS"
 	  RUBY_LIBS=
 	fi
       else