diff --git a/numeric.c b/numeric.c
index c67b97ee55..9bbce09e64 100644
--- a/numeric.c
+++ b/numeric.c
@@ -1864,20 +1864,10 @@ ruby_num_interval_step_size(VALUE from, VALUE to, VALUE step, int excl)
     if (NIL_P(step)) {							\
         step = INT2FIX(1);						\
     }									\
-    else {								\
-        if (!rb_obj_is_kind_of(step, rb_cNumeric)) {			\
-            rb_raise(rb_eTypeError, "step must be numeric");		\
-        }								\
-    }									\
     desc = negative_int_p(step);					\
     if (NIL_P(to)) {							\
         to = desc ? DBL2NUM(-INFINITY) : DBL2NUM(INFINITY);		\
     }									\
-    else {								\
-        if (!rb_obj_is_kind_of(to, rb_cNumeric)) {			\
-            rb_raise(rb_eTypeError, "limit must be numeric");		\
-        }								\
-    }									\
 } while (0)
 
 #define NUM_STEP_GET_INF(to, desc, inf) do {				\
diff --git a/test/ruby/test_float.rb b/test/ruby/test_float.rb
index f011c2b062..127c8c6f92 100644
--- a/test/ruby/test_float.rb
+++ b/test/ruby/test_float.rb
@@ -558,7 +558,7 @@ class TestFloat < Test::Unit::TestCase
   end
 
   def test_num2dbl
-    assert_raise(TypeError) do
+    assert_raise(ArgumentError) do
       1.0.step(2.0, "0.5") {}
     end
     assert_raise(TypeError) do
diff --git a/test/ruby/test_numeric.rb b/test/ruby/test_numeric.rb
index 4e7aef2777..e82269165b 100644
--- a/test/ruby/test_numeric.rb
+++ b/test/ruby/test_numeric.rb
@@ -227,8 +227,8 @@ class TestNumeric < Test::Unit::TestCase
     assert_raise(ArgumentError) { 1.step(10, 1, 0).size }
     assert_raise(ArgumentError) { 1.step(10, 0) { } }
     assert_raise(ArgumentError) { 1.step(10, 0).size }
-    assert_raise(TypeError) { 1.step(10, "1") { } }
-    assert_raise(TypeError) { 1.step(10, "1").size }
+    assert_raise(ArgumentError) { 1.step(10, "1") { } }
+    assert_raise(ArgumentError) { 1.step(10, "1").size }
     assert_raise(TypeError) { 1.step(10, nil) { } }
     assert_raise(TypeError) { 1.step(10, nil).size }
     assert_nothing_raised { 1.step(by: 0, to: nil) }