diff --git a/.rubocop_rubyzip.yml b/.rubocop_rubyzip.yml
index b892bbe3..3030f8a0 100644
--- a/.rubocop_rubyzip.yml
+++ b/.rubocop_rubyzip.yml
@@ -73,6 +73,12 @@ Style/BlockDelimiters:
 Style/ClassAndModuleChildren:
   Enabled: false
 
+# Offense count: 15
+# Cop supports --auto-correct.
+# Configuration parameters: EnforcedStyle, SupportedStyles.
+Style/ClassCheck:
+  Enabled: false
+
 # Offense count: 77
 Style/Documentation:
   Enabled: false
diff --git a/lib/zip/central_directory.rb b/lib/zip/central_directory.rb
index 5b0a3fe6..cb7e2da7 100644
--- a/lib/zip/central_directory.rb
+++ b/lib/zip/central_directory.rb
@@ -17,7 +17,7 @@ def entries
 
     def initialize(entries = EntrySet.new, comment = '') #:nodoc:
       super()
-      @entry_set = entries.is_a?(EntrySet) ? entries : EntrySet.new(entries)
+      @entry_set = entries.kind_of?(EntrySet) ? entries : EntrySet.new(entries)
       @comment   = comment
     end
 
@@ -197,7 +197,7 @@ def self.read_from_stream(io) #:nodoc:
     end
 
     def ==(other) #:nodoc:
-      return false unless other.is_a?(CentralDirectory)
+      return false unless other.kind_of?(CentralDirectory)
       @entry_set.entries.sort == other.entries.sort && comment == other.comment
     end
   end
diff --git a/lib/zip/entry_set.rb b/lib/zip/entry_set.rb
index e083b0e2..dc6e53e2 100644
--- a/lib/zip/entry_set.rb
+++ b/lib/zip/entry_set.rb
@@ -49,7 +49,7 @@ def dup
     end
 
     def ==(other)
-      return false unless other.is_a?(EntrySet)
+      return false unless other.kind_of?(EntrySet)
       @entry_set.values == other.entry_set.values
     end
 
diff --git a/lib/zip/file.rb b/lib/zip/file.rb
index 16cfc005..3cc4c352 100644
--- a/lib/zip/file.rb
+++ b/lib/zip/file.rb
@@ -235,7 +235,7 @@ def get_input_stream(entry, &aProc)
     # File.open method.
     def get_output_stream(entry, permission_int = nil, comment = nil, extra = nil, compressed_size = nil, crc = nil, compression_method = nil, size = nil, time = nil,  &aProc)
       new_entry =
-        if entry.is_a?(Entry)
+        if entry.kind_of?(Entry)
           entry
         else
           Entry.new(@name, entry.to_s, comment, extra, compressed_size, crc, compression_method, size, time)
@@ -264,7 +264,7 @@ def read(entry)
     def add(entry, src_path, &continue_on_exists_proc)
       continue_on_exists_proc ||= proc { ::Zip.continue_on_exists_proc }
       check_entry_exists(entry, continue_on_exists_proc, 'add')
-      new_entry = entry.is_a?(::Zip::Entry) ? entry : ::Zip::Entry.new(@name, entry.to_s)
+      new_entry = entry.kind_of?(::Zip::Entry) ? entry : ::Zip::Entry.new(@name, entry.to_s)
       new_entry.gather_fileinfo_from_srcpath(src_path)
       new_entry.dirty = true
       @entry_set << new_entry
diff --git a/lib/zip/output_stream.rb b/lib/zip/output_stream.rb
index c320566f..70117e24 100644
--- a/lib/zip/output_stream.rb
+++ b/lib/zip/output_stream.rb
@@ -87,7 +87,7 @@ def close_buffer
     # +entry+ can be a ZipEntry object or a string.
     def put_next_entry(entry_name, comment = nil, extra = nil, compression_method = Entry::DEFLATED, level = Zip.default_compression)
       raise Error, 'zip stream is closed' if @closed
-      if entry_name.is_a?(Entry)
+      if entry_name.kind_of?(Entry)
         new_entry = entry_name
       else
         new_entry = Entry.new(@file_name, entry_name.to_s)
diff --git a/test/filesystem/file_nonmutating_test.rb b/test/filesystem/file_nonmutating_test.rb
index 7ce00021..50184b78 100644
--- a/test/filesystem/file_nonmutating_test.rb
+++ b/test/filesystem/file_nonmutating_test.rb
@@ -384,7 +384,7 @@ def test_readlink
 
   def test_stat
     s = @zip_file.file.stat('file1')
-    assert(s.is_a?(File::Stat)) # It pretends
+    assert(s.kind_of?(File::Stat)) # It pretends
     assert_raises(Errno::ENOENT, 'No such file or directory - noSuchFile') do
       @zip_file.file.stat('noSuchFile')
     end
diff --git a/test/ioextras/fake_io_test.rb b/test/ioextras/fake_io_test.rb
index 04059715..00726c48 100644
--- a/test/ioextras/fake_io_test.rb
+++ b/test/ioextras/fake_io_test.rb
@@ -9,10 +9,10 @@ class FakeIOUsingClass
   def test_kind_of?
     obj = FakeIOUsingClass.new
 
-    assert(obj.is_a?(Object))
-    assert(obj.is_a?(FakeIOUsingClass))
-    assert(obj.is_a?(IO))
-    assert(!obj.is_a?(Fixnum))
-    assert(!obj.is_a?(String))
+    assert(obj.kind_of?(Object))
+    assert(obj.kind_of?(FakeIOUsingClass))
+    assert(obj.kind_of?(IO))
+    assert(!obj.kind_of?(Fixnum))
+    assert(!obj.kind_of?(String))
   end
 end
diff --git a/test/output_stream_test.rb b/test/output_stream_test.rb
index f6ff55d2..a7725e22 100644
--- a/test/output_stream_test.rb
+++ b/test/output_stream_test.rb
@@ -58,9 +58,9 @@ def test_cannot_open_file
     begin
       ::Zip::OutputStream.open(name)
     rescue Exception
-      assert($!.is_a?(Errno::EISDIR) || # Linux
-                 $!.is_a?(Errno::EEXIST) || # Windows/cygwin
-                 $!.is_a?(Errno::EACCES), # Windows
+      assert($!.kind_of?(Errno::EISDIR) || # Linux
+                 $!.kind_of?(Errno::EEXIST) || # Windows/cygwin
+                 $!.kind_of?(Errno::EACCES), # Windows
              "Expected Errno::EISDIR (or on win/cygwin: Errno::EEXIST), but was: #{$!.class}")
     end
   end