diff --git a/internal.h b/internal.h
index f72a7921ee..da6b5fa236 100644
--- a/internal.h
+++ b/internal.h
@@ -810,6 +810,7 @@ VALUE rb_rational_reciprocal(VALUE x);
 /* re.c */
 VALUE rb_reg_compile(VALUE str, int options, const char *sourcefile, int sourceline);
 VALUE rb_reg_check_preprocess(VALUE);
+long rb_reg_search0(VALUE, VALUE, long, int, int);
 
 /* signal.c */
 int rb_get_next_signal(void);
@@ -978,9 +979,6 @@ VALUE rb_gcd_normal(VALUE self, VALUE other);
 VALUE rb_gcd_gmp(VALUE x, VALUE y);
 #endif
 
-/* re.c */
-long rb_reg_search0(VALUE, VALUE, long, int, int);
-
 /* util.c */
 extern const signed char ruby_digit36_to_number_table[];