diff --git a/include/mruby/internal.h b/include/mruby/internal.h
index f1278a402..78f1d15ae 100644
--- a/include/mruby/internal.h
+++ b/include/mruby/internal.h
@@ -27,6 +27,8 @@ mrb_value mrb_mod_const_missing(mrb_state *mrb, mrb_value mod);
 mrb_value mrb_const_missing(mrb_state *mrb, mrb_value mod, mrb_sym sym);
 #endif
 
+mrb_value mrb_obj_equal_m(mrb_state *mrb, mrb_value);
+
 /* debug */
 size_t mrb_packed_int_len(uint32_t num);
 size_t mrb_packed_int_encode(uint32_t num, uint8_t *p, uint8_t *pend);
diff --git a/src/kernel.c b/src/kernel.c
index 285bb4fb3..c87f2046a 100644
--- a/src/kernel.c
+++ b/src/kernel.c
@@ -556,8 +556,6 @@ mrb_encoding(mrb_state *mrb, mrb_value self)
 #endif
 }
 
-mrb_value mrb_obj_equal_m(mrb_state *mrb, mrb_value);
-
 void
 mrb_init_kernel(mrb_state *mrb)
 {