diff --git a/mrbgems/mruby-bin-mrbc/tools/mrbc/mrbc.c b/mrbgems/mruby-bin-mrbc/tools/mrbc/mrbc.c
index aae91b285..a72e07701 100644
--- a/mrbgems/mruby-bin-mrbc/tools/mrbc/mrbc.c
+++ b/mrbgems/mruby-bin-mrbc/tools/mrbc/mrbc.c
@@ -396,6 +396,10 @@ mrb_value mrb_complex_mul(mrb_state *mrb, mrb_value x, mrb_value y)
 {
   return mrb_nil_value();
 }
+mrb_value mrb_complex_div(mrb_state *mrb, mrb_value x, mrb_value y)
+{
+  return mrb_nil_value();
+}
 mrb_value mrb_complex_to_i(mrb_state *mrb, mrb_value x)
 {
   return mrb_nil_value();
@@ -423,6 +427,10 @@ mrb_value mrb_rational_mul(mrb_state *mrb, mrb_value x, mrb_value y)
 {
   return mrb_nil_value();
 }
+mrb_value mrb_rational_div(mrb_state *mrb, mrb_value x, mrb_value y)
+{
+  return mrb_nil_value();
+}
 mrb_value mrb_rational_to_i(mrb_state *mrb, mrb_value x)
 {
   return mrb_nil_value();
diff --git a/mrbgems/mruby-complex/src/complex.c b/mrbgems/mruby-complex/src/complex.c
index 870e54a6a..2cd111ded 100644
--- a/mrbgems/mruby-complex/src/complex.c
+++ b/mrbgems/mruby-complex/src/complex.c
@@ -348,61 +348,6 @@ complex_div(mrb_state *mrb, mrb_value x)
   return mrb_complex_div(mrb, x, y);
 }
 
-mrb_int mrb_div_int(mrb_state *mrb, mrb_int x, mrb_int y);
-mrb_value mrb_rational_new(mrb_state *mrb, mrb_int n, mrb_int d);
-mrb_value mrb_rational_div(mrb_state *mrb, mrb_value x, mrb_value y);
-
-/* 15.2.8.3.4  */
-/*
- * redefine Integer#/
- */
-static mrb_value
-complex_int_div(mrb_state *mrb, mrb_value x)
-{
-  mrb_value y = mrb_get_arg1(mrb);
-  mrb_int a = mrb_integer(x);
-
-  if (mrb_integer_p(y)) {
-    mrb_int div = mrb_div_int(mrb, a, mrb_integer(y));
-    return mrb_int_value(mrb, div);
-  }
-  switch (mrb_type(y)) {
-#ifdef MRB_USE_RATIONAL
-  case MRB_TT_RATIONAL:
-    return mrb_rational_div(mrb, mrb_rational_new(mrb, a, 1), y);
-#endif
-  case MRB_TT_COMPLEX:
-    x = complex_new(mrb, (mrb_float)a, 0);
-    return complex_div(mrb, x);
-  default:
-    return mrb_float_value(mrb, mrb_div_float((mrb_float)a, mrb_as_float(mrb, y)));
-  }
-}
-
-/* 15.2.9.3.19(x) */
-/*
- * redefine Integer#quo
- */
-
-static mrb_value
-complex_int_quo(mrb_state *mrb, mrb_value x)
-{
-  mrb_value y = mrb_get_arg1(mrb);
-  mrb_int a = mrb_integer(x);
-
-  switch (mrb_type(y)) {
-#ifdef MRB_USE_RATIONAL
-  case MRB_TT_RATIONAL:
-    return mrb_rational_div(mrb, mrb_rational_new(mrb, a, 1), y);
-#endif
-  case MRB_TT_COMPLEX:
-    x = complex_new(mrb, (mrb_float)a, 0);
-    return complex_div(mrb, x);
-  default:
-    return mrb_float_value(mrb, mrb_div_float((mrb_float)a, mrb_as_float(mrb, y)));
-  }
-}
-
 static mrb_value
 complex_float_div(mrb_state *mrb, mrb_value x)
 {
@@ -447,8 +392,6 @@ void mrb_mruby_complex_gem_init(mrb_state *mrb)
   mrb_define_method(mrb, comp, "/", complex_div, MRB_ARGS_REQ(1));
   mrb_define_method(mrb, comp, "quo", complex_div, MRB_ARGS_REQ(1));
   mrb_define_method(mrb, comp, "==", complex_eq, MRB_ARGS_REQ(1));
-  mrb_define_method(mrb, mrb->integer_class, "/", complex_int_div, MRB_ARGS_REQ(1)); /* override */
-  mrb_define_method(mrb, mrb->integer_class, "quo", complex_int_quo, MRB_ARGS_REQ(1)); /* override */
   mrb_define_method(mrb, mrb->float_class, "/", complex_float_div, MRB_ARGS_REQ(1)); /* override */
   mrb_define_method(mrb, mrb->float_class, "quo", complex_float_div, MRB_ARGS_REQ(1)); /* override */
 }
diff --git a/mrbgems/mruby-rational/src/rational.c b/mrbgems/mruby-rational/src/rational.c
index 0730c3ecb..8fed218d3 100644
--- a/mrbgems/mruby-rational/src/rational.c
+++ b/mrbgems/mruby-rational/src/rational.c
@@ -664,7 +664,8 @@ mrb_rational_div(mrb_state *mrb, mrb_value x, mrb_value y)
   }
 }
 
-mrb_value rational_div(mrb_state *mrb, mrb_value x)
+static mrb_value
+rational_div(mrb_state *mrb, mrb_value x)
 {
   mrb_value y = mrb_get_arg1(mrb);
   return mrb_rational_div(mrb, x, y);
@@ -672,62 +673,6 @@ mrb_value rational_div(mrb_state *mrb, mrb_value x)
 
 mrb_int mrb_div_int(mrb_state *, mrb_int, mrb_int);
 
-#ifndef MRB_USE_COMPLEX
-/* 15.2.8.3.4  */
-/*
- * redefine Integer#/
- */
-static mrb_value
-rational_int_div(mrb_state *mrb, mrb_value x)
-{
-  mrb_value y = mrb_get_arg1(mrb);
-  mrb_int a = mrb_integer(x);
-
-  if (mrb_integer_p(y)) {
-    mrb_int div = mrb_div_int(mrb, a, mrb_integer(y));
-    return mrb_int_value(mrb, div);
-  }
-  switch (mrb_type(y)) {
-  case MRB_TT_RATIONAL:
-    return rational_div(mrb, rational_new(mrb, a, 1), y);
-  default:
-#ifdef MRB_NO_FLOAT
-  case MRB_TT_FLOAT:
-    mrb_raise(mrb, E_TYPE_ERROR, "non integer multiplication");
-#else
-    return mrb_float_value(mrb, mrb_div_float((mrb_float)a, mrb_as_float(mrb, y)));
-#endif
-  }
-}
-
-/* 15.2.9.3.19(x) */
-/*
- * redefine Integer#quo
- */
-
-static mrb_value
-rational_int_quo(mrb_state *mrb, mrb_value x)
-{
-  mrb_value y = mrb_get_arg1(mrb);
-  mrb_int a = mrb_integer(x);
-
-  if (mrb_integer_p(y)) {
-    return rational_new(mrb, a, mrb_integer(y));
-  }
-  switch (mrb_type(y)) {
-  case MRB_TT_RATIONAL:
-    x = rational_new(mrb, a, 1);
-    return mrb_rational_div(mrb, x, y);
-  default:
-#ifdef MRB_NO_FLOAT
-    mrb_raise(mrb, E_TYPE_ERROR, "non integer multiplication");
-#else
-    return mrb_float_value(mrb, mrb_div_float((mrb_float)a, mrb_as_float(mrb, y)));
-#endif
-  }
-}
-#endif  /* !MRB_USE_COMPLEX */
-
 void mrb_mruby_rational_gem_init(mrb_state *mrb)
 {
   struct RClass *rat;
@@ -753,10 +698,6 @@ void mrb_mruby_rational_gem_init(mrb_state *mrb)
   mrb_define_method(mrb, rat, "/", rational_div, MRB_ARGS_REQ(1));
   mrb_define_method(mrb, rat, "quo", rational_div, MRB_ARGS_REQ(1));
   mrb_define_method(mrb, mrb->integer_class, "to_r", fix_to_r, MRB_ARGS_NONE());
-#ifndef MRB_USE_COMPLEX
-  mrb_define_method(mrb, mrb->integer_class, "/", rational_int_div, MRB_ARGS_REQ(1)); /* override */
-  mrb_define_method(mrb, mrb->integer_class, "quo", rational_int_quo, MRB_ARGS_REQ(1)); /* override */
-#endif
   mrb_define_method(mrb, mrb->kernel_module, "Rational", rational_m, MRB_ARGS_ARG(1,1));
 }
 
diff --git a/src/numeric.c b/src/numeric.c
index aa07853ac..d4e124c2b 100644
--- a/src/numeric.c
+++ b/src/numeric.c
@@ -25,12 +25,14 @@ mrb_value mrb_complex_new(mrb_state *mrb, mrb_float x, mrb_float y);
 mrb_value mrb_complex_add(mrb_state *mrb, mrb_value x, mrb_value y);
 mrb_value mrb_complex_sub(mrb_state *mrb, mrb_value x, mrb_value y);
 mrb_value mrb_complex_mul(mrb_state *mrb, mrb_value x, mrb_value y);
+mrb_value mrb_complex_div(mrb_state *mrb, mrb_value x, mrb_value y);
 #endif
 
 mrb_value mrb_rational_new(mrb_state *mrb, mrb_int x, mrb_int y);
 mrb_value mrb_rational_add(mrb_state *mrb, mrb_value x, mrb_value y);
 mrb_value mrb_rational_sub(mrb_state *mrb, mrb_value x, mrb_value y);
 mrb_value mrb_rational_mul(mrb_state *mrb, mrb_value x, mrb_value y);
+mrb_value mrb_rational_div(mrb_state *mrb, mrb_value x, mrb_value y);
 
 void
 mrb_int_overflow(mrb_state *mrb, const char *reason)
@@ -138,11 +140,23 @@ int_div(mrb_state *mrb, mrb_value x)
     mrb_int div = mrb_div_int(mrb, a, mrb_integer(y));
     return mrb_int_value(mrb, div);
   }
-#ifdef MRB_NO_FLOAT
-  mrb_raise(mrb, E_TYPE_ERROR, "non integer division");
-#else
-  return mrb_float_value(mrb, mrb_div_float((mrb_float)a, mrb_as_float(mrb, y)));
+  switch (mrb_type(y)) {
+#ifdef MRB_USE_RATIONAL
+  case MRB_TT_RATIONAL:
+    return mrb_rational_div(mrb, mrb_rational_new(mrb, a, 1), y);
 #endif
+#ifdef MRB_USE_COMPLEX
+  case MRB_TT_COMPLEX:
+    x = mrb_complex_new(mrb, (mrb_float)a, 0);
+    return mrb_complex_div(mrb, x, y);
+#endif
+  default:
+#ifdef MRB_NO_FLOAT
+    mrb_raise(mrb, E_TYPE_ERROR, "non integer division");
+#else
+    return mrb_float_value(mrb, mrb_div_float((mrb_float)a, mrb_as_float(mrb, y)));
+#endif
+  }
 }
 
 /* 15.2.9.3.19(x) */
@@ -172,8 +186,12 @@ int_idiv(mrb_state *mrb, mrb_value x)
 }
 
 static mrb_value
-int_quo(mrb_state *mrb, mrb_value xv)
+int_quo(mrb_state *mrb, mrb_value x)
 {
+  mrb_value y = mrb_get_arg1(mrb);
+  mrb_int a = mrb_integer(x);
+
+#ifndef MRB_USE_RATIONAL
 #ifdef MRB_NO_FLOAT
   return int_idiv(mrb, xv);
 #else
@@ -185,6 +203,22 @@ int_quo(mrb_state *mrb, mrb_value xv)
   }
   return mrb_float_value(mrb, mrb_integer(xv) / y);
 #endif
+#else
+  if (mrb_integer_p(y) && mrb_class_defined_id(mrb, MRB_SYM(Rational))) {
+    return mrb_rational_new(mrb, a, mrb_integer(y));
+  }
+  switch (mrb_type(y)) {
+  case MRB_TT_RATIONAL:
+    x = mrb_rational_new(mrb, a, 1);
+    return mrb_rational_div(mrb, x, y);
+  default:
+#ifdef MRB_NO_FLOAT
+    mrb_raise(mrb, E_TYPE_ERROR, "non integer division");
+#else
+    return mrb_float_value(mrb, mrb_div_float((mrb_float)a, mrb_as_float(mrb, y)));
+#endif
+  }
+#endif
 }
 
 static mrb_value
diff --git a/test/t/integer.rb b/test/t/integer.rb
index d4076f38a..71066bfb1 100644
--- a/test/t/integer.rb
+++ b/test/t/integer.rb
@@ -45,10 +45,17 @@ assert('Integer#/', '15.2.8.3.4') do
   assert_equal 2.0, b
 end
 
-assert('Integer#quo') do
-  a = 6.quo(5)
-  assert_equal 1.2, a
-end if Object.const_defined?(:Float)
+if Object.const_defined?(:Rational)
+  assert('Integer#quo') do
+    a = 6.quo(5)
+    assert_equal 5/6r, a
+  end
+elsif Object.const_defined?(:Float)
+  assert('Integer#quo') do
+    a = 6.quo(5)
+    assert_equal 1.2, a
+  end
+end
 
 assert('Integer#%', '15.2.8.3.5') do
   a = 1%1