diff --git a/array.c b/array.c
index bcf98fc012..56f3584e1d 100644
--- a/array.c
+++ b/array.c
@@ -3393,6 +3393,9 @@ rb_ary_sort_bang(VALUE ary)
                 rb_ary_unshare(ary);
                 FL_SET_EMBED(ary);
             }
+            if (ARY_EMBED_LEN(tmp) > ARY_CAPA(ary)) {
+                ary_resize_capa(ary, ARY_EMBED_LEN(tmp));
+            }
             ary_memcpy(ary, 0, ARY_EMBED_LEN(tmp), ARY_EMBED_PTR(tmp));
             ARY_SET_LEN(ary, ARY_EMBED_LEN(tmp));
         }
diff --git a/test/ruby/test_array.rb b/test/ruby/test_array.rb
index 6e84bdbd02..9560fca958 100644
--- a/test/ruby/test_array.rb
+++ b/test/ruby/test_array.rb
@@ -3556,6 +3556,15 @@ class TestArray < Test::Unit::TestCase
     assert_equal(10000, eval(lit).size)
   end
 
+  def test_array_safely_modified_by_sort_block
+    var_0 = (1..70).to_a
+    var_0.sort! do |var_0_block_129, var_1_block_129|
+      var_0.pop
+      var_1_block_129 <=> var_0_block_129
+    end.shift(3)
+    assert_equal((1..67).to_a.reverse, var_0)
+  end
+
   private
   def need_continuation
     unless respond_to?(:callcc, true)