diff --git a/ext/stringio/stringio.c b/ext/stringio/stringio.c
index f5213f2fc0..e89a1d780c 100644
--- a/ext/stringio/stringio.c
+++ b/ext/stringio/stringio.c
@@ -12,7 +12,7 @@
 
 **********************************************************************/
 
-#define STRINGIO_VERSION "3.0.8"
+#define STRINGIO_VERSION "3.0.9"
 
 #include "ruby.h"
 #include "ruby/io.h"