diff --git a/src/codegen.c b/src/codegen.c
index 4f7eaea79..32530e80f 100644
--- a/src/codegen.c
+++ b/src/codegen.c
@@ -2895,7 +2895,7 @@ codedump_recur(mrb_state *mrb, mrb_irep *irep)
 void
 codedump_all(mrb_state *mrb, struct RProc *proc)
 {
-  return codedump_recur(mrb, proc->body.irep);
+  codedump_recur(mrb, proc->body.irep);
 }
 
 struct RProc*