diff --git a/include/ruby/ruby.h b/include/ruby/ruby.h
index 9e9423e810..649ece290a 100644
--- a/include/ruby/ruby.h
+++ b/include/ruby/ruby.h
@@ -2163,6 +2163,11 @@ rb_array_const_ptr(VALUE a)
     return rb_array_const_ptr_transient(a);
 }
 
+/* fix related to r66200 */
+#ifdef __INTEL_COMPILER
+VALUE *rb_ary_ptr_use_start(VALUE ary);
+#endif
+
 /* internal function. do not use this function */
 static inline VALUE *
 rb_array_ptr_use_start(VALUE a, int allow_transient)
diff --git a/internal.h b/internal.h
index 84603bb911..a92b0d4a54 100644
--- a/internal.h
+++ b/internal.h
@@ -1296,7 +1296,6 @@ VALUE rb_to_array_type(VALUE obj);
 VALUE rb_check_to_array(VALUE ary);
 VALUE rb_ary_tmp_new_from_values(VALUE, long, const VALUE *);
 VALUE rb_ary_behead(VALUE, long);
-VALUE *rb_ary_ptr_use_start(VALUE ary);
 #if defined(__GNUC__) && defined(HAVE_VA_ARGS_MACRO)
 #define rb_ary_new_from_args(n, ...) \
     __extension__ ({ \