diff --git a/ext/stringio/stringio.c b/ext/stringio/stringio.c
index 9240929646d5ea..56fb044a3a299f 100644
--- a/ext/stringio/stringio.c
+++ b/ext/stringio/stringio.c
@@ -747,7 +747,7 @@ strio_copy(VALUE copy, VALUE orig)
  *   lineno -> current_line_number
  *
  * Returns the current line number in +self+;
- * see {Line Number}[rdoc-ref:IO@Line+Number].
+ * see {Line Number}[rdoc-ref:StringIO@Line+Number].
  */
 static VALUE
 strio_get_lineno(VALUE self)
@@ -760,7 +760,7 @@ strio_get_lineno(VALUE self)
  *   lineno = new_line_number -> new_line_number
  *
  * Sets the current line number in +self+ to the given +new_line_number+;
- * see {Line Number}[rdoc-ref:IO@Line+Number].
+ * see {Line Number}[rdoc-ref:StringIO@Line+Number].
  */
 static VALUE
 strio_set_lineno(VALUE self, VALUE lineno)
@@ -835,7 +835,7 @@ strio_reopen(int argc, VALUE *argv, VALUE self)
  *   pos -> stream_position
  *
  * Returns the current position (in bytes);
- * see {Position}[rdoc-ref:IO@Position].
+ * see {Position}[rdoc-ref:StringIO@Position].
  */
 static VALUE
 strio_get_pos(VALUE self)
@@ -848,7 +848,7 @@ strio_get_pos(VALUE self)
  *   pos = new_position -> new_position
  *
  * Sets the current position (in bytes);
- * see {Position}[rdoc-ref:IO@Position].
+ * see {Position}[rdoc-ref:StringIO@Position].
  */
 static VALUE
 strio_set_pos(VALUE self, VALUE pos)