diff --git a/ChangeLog b/ChangeLog
index 5c5d08dbcf..cf151e994f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+Sat Aug 27 20:46:05 2011  Kazuki Tsujimoto  <kazuki@callcc.net>
+
+	* vm.c (rb_vm_rewrite_dfp_in_errinfo): change return type
+	  to suppress a warning.
+
+	* vm_core.h: ditto.
+
 Sat Aug 27 19:04:06 2011  NARUSE, Yui  <naruse@ruby-lang.org>
 
 	* internal.h (rb_strftime_timespec): moved from time.c and define only
diff --git a/vm.c b/vm.c
index 7a21b97159..80b0857de5 100644
--- a/vm.c
+++ b/vm.c
@@ -473,7 +473,7 @@ rb_vm_make_env_object(rb_thread_t * th, rb_control_frame_t *cfp)
     return envval;
 }
 
-VALUE
+void
 rb_vm_rewrite_dfp_in_errinfo(rb_thread_t *th, rb_control_frame_t *cfp)
 {
     /* rewrite dfp in errinfo to point to heap */
diff --git a/vm_core.h b/vm_core.h
index 5680f136e7..e8dbdd9c5a 100644
--- a/vm_core.h
+++ b/vm_core.h
@@ -649,7 +649,7 @@ VALUE rb_vm_invoke_proc(rb_thread_t *th, rb_proc_t *proc, VALUE self,
 			int argc, const VALUE *argv, const rb_block_t *blockptr);
 VALUE rb_vm_make_proc(rb_thread_t *th, const rb_block_t *block, VALUE klass);
 VALUE rb_vm_make_env_object(rb_thread_t *th, rb_control_frame_t *cfp);
-VALUE rb_vm_rewrite_dfp_in_errinfo(rb_thread_t *th, rb_control_frame_t *cfp);
+void rb_vm_rewrite_dfp_in_errinfo(rb_thread_t *th, rb_control_frame_t *cfp);
 void rb_vm_inc_const_missing_count(void);
 void rb_vm_gvl_destroy(rb_vm_t *vm);
 VALUE rb_vm_call(rb_thread_t *th, VALUE recv, VALUE id, int argc,