diff --git a/Gemfile.lock b/Gemfile.lock
index ab95540..44cce82 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -11,12 +11,12 @@ GEM
     bindata (2.4.4)
     coderay (1.1.2)
     diff-lcs (1.3)
-    docile (1.3.0)
+    docile (1.3.1)
     jaro_winkler (1.5.1)
     json (2.1.0)
     method_source (0.9.0)
     parallel (1.12.1)
-    parser (2.5.1.0)
+    parser (2.5.1.2)
       ast (~> 2.4.0)
     powerpack (0.1.2)
     pry (0.11.3)
@@ -30,22 +30,22 @@ GEM
       rspec-mocks (~> 3.8.0)
     rspec-core (3.8.0)
       rspec-support (~> 3.8.0)
-    rspec-expectations (3.8.0)
+    rspec-expectations (3.8.2)
       diff-lcs (>= 1.2.0, < 2.0)
       rspec-support (~> 3.8.0)
     rspec-mocks (3.8.0)
       diff-lcs (>= 1.2.0, < 2.0)
       rspec-support (~> 3.8.0)
     rspec-support (3.8.0)
-    rubocop (0.57.2)
+    rubocop (0.59.2)
       jaro_winkler (~> 1.5.1)
       parallel (~> 1.10)
-      parser (>= 2.5)
+      parser (>= 2.5, != 2.5.1.1)
       powerpack (~> 0.1)
       rainbow (>= 2.2.2, < 4.0)
       ruby-progressbar (~> 1.7)
       unicode-display_width (~> 1.0, >= 1.0.1)
-    ruby-progressbar (1.9.0)
+    ruby-progressbar (1.10.0)
     simplecov (0.16.1)
       docile (~> 1.1)
       json (>= 1.8, < 3)
@@ -62,9 +62,9 @@ DEPENDENCIES
   pry (~> 0.10)
   rake (~> 12.1)
   rspec (~> 3.7)
-  rubocop (~> 0.54)
+  rubocop (~> 0.59)
   simplecov (~> 0.16.1)
   yard (~> 0.9)
 
 BUNDLED WITH
-   1.16.1
+   1.16.6
diff --git a/elftools.gemspec b/elftools.gemspec
index 9d015c0..4b09f29 100644
--- a/elftools.gemspec
+++ b/elftools.gemspec
@@ -24,7 +24,7 @@ Gem::Specification.new do |s|
   s.add_development_dependency 'pry', '~> 0.10'
   s.add_development_dependency 'rake', '~> 12.1'
   s.add_development_dependency 'rspec', '~> 3.7'
-  s.add_development_dependency 'rubocop', '~> 0.54'
+  s.add_development_dependency 'rubocop', '~> 0.59'
   s.add_development_dependency 'simplecov', '~> 0.16.1'
   s.add_development_dependency 'yard', '~> 0.9'
 end
diff --git a/lib/elftools/dynamic.rb b/lib/elftools/dynamic.rb
index 0f58376..377b454 100644
--- a/lib/elftools/dynamic.rb
+++ b/lib/elftools/dynamic.rb
@@ -18,6 +18,7 @@ module Dynamic
     #   Otherwise, return array of tags.
     def each_tags(&block)
       return enum_for(:each_tags) unless block_given?
+
       arr = []
       0.step do |i|
         tag = tag_at(i).tap(&block)
@@ -77,8 +78,10 @@ def tag_by_type(type)
     # @return [ELFTools::Dynamic::Tag] The desired tag.
     def tag_at(n)
       return if n < 0
+
       @tag_at_map ||= {}
       return @tag_at_map[n] if @tag_at_map[n]
+
       dyn = Structs::ELF_Dyn.new(endian: endian)
       dyn.elf_class = header.elf_class
       stream.pos = tag_start + n * dyn.num_bytes
@@ -153,6 +156,7 @@ def name?
       # @return [String, nil] The name.
       def name
         return nil unless name?
+
         Util.cstring(stream, @str_offset.call + header.d_val.to_i)
       end
     end
diff --git a/lib/elftools/elf_file.rb b/lib/elftools/elf_file.rb
index 3530e1c..d5a8634 100644
--- a/lib/elftools/elf_file.rb
+++ b/lib/elftools/elf_file.rb
@@ -32,6 +32,7 @@ def initialize(stream)
     # @return [ELFTools::Structs::ELF_Ehdr] The header.
     def header
       return @header if defined?(@header)
+
       stream.pos = 0
       @header = Structs::ELF_Ehdr.new(endian: endian, offset: stream.pos)
       @header.elf_class = elf_class
@@ -49,8 +50,10 @@ def header
     def build_id
       section = section_by_name('.note.gnu.build-id')
       return nil if section.nil?
+
       note = section.notes.first
       return nil if note.nil?
+
       note.desc.unpack('H*').first
     end
 
@@ -116,6 +119,7 @@ def section_by_name(name)
     #   otherwise, the whole sections will be returned.
     def each_sections(&block)
       return enum_for(:each_sections) unless block_given?
+
       Array.new(num_sections) do |i|
         section_at(i).tap(&block)
       end
@@ -188,6 +192,7 @@ def num_segments
     #   Whole segments will be returned.
     def each_segments(&block)
       return enum_for(:each_segments) unless block_given?
+
       Array.new(num_segments) do |i|
         segment_at(i).tap(&block)
       end
@@ -324,6 +329,7 @@ def loaded_headers
       explore = lambda do |obj|
         return obj if obj.is_a?(::ELFTools::Structs::ELFStruct)
         return obj.map(&explore) if obj.is_a?(Array)
+
         obj.instance_variables.map do |s|
           explore.call(obj.instance_variable_get(s))
         end
@@ -335,12 +341,14 @@ def identify
       stream.pos = 0
       magic = stream.read(4)
       raise ELFError, "Invalid magic number #{magic.inspect}" unless magic == Constants::ELFMAG
+
       ei_class = stream.read(1).ord
       @elf_class = {
         1 => 32,
         2 => 64
       }[ei_class]
       raise ELFError, format('Invalid EI_CLASS "\x%02x"', ei_class) if elf_class.nil?
+
       ei_data = stream.read(1).ord
       @endian = {
         1 => :little,
diff --git a/lib/elftools/lazy_array.rb b/lib/elftools/lazy_array.rb
index 908ff7f..7756b80 100644
--- a/lib/elftools/lazy_array.rb
+++ b/lib/elftools/lazy_array.rb
@@ -38,6 +38,7 @@ def initialize(size, &block)
     def [](i)
       # XXX: support negative index?
       return nil if i < 0 || i >= @internal.size
+
       @internal[i] ||= @block.call(i)
     end
   end
diff --git a/lib/elftools/note.rb b/lib/elftools/note.rb
index 558a79f..989affa 100644
--- a/lib/elftools/note.rb
+++ b/lib/elftools/note.rb
@@ -41,6 +41,7 @@ module Note
     #   Otherwise, return the array of notes.
     def each_notes
       return enum_for(:each_notes) unless block_given?
+
       @notes_offset_map ||= {}
       cur = note_start
       notes = []
@@ -101,6 +102,7 @@ def initialize(header, stream, offset)
       # @return [String] The name.
       def name
         return @name if @name
+
         stream.pos = @offset + SIZE_OF_NHDR
         @name = stream.read(header.n_namesz)[0..-2]
       end
@@ -108,7 +110,8 @@ def name
       # Description of this note.
       # @return [String] The description.
       def desc
-        return @desc if @desc
+        return @desc if instance_variable_defined?(:@desc)
+
         stream.pos = @offset + SIZE_OF_NHDR + Util.align(header.n_namesz, 2)
         @desc = stream.read(header.n_descsz)
       end
diff --git a/lib/elftools/sections/relocation_section.rb b/lib/elftools/sections/relocation_section.rb
index 3e63380..ba35cff 100644
--- a/lib/elftools/sections/relocation_section.rb
+++ b/lib/elftools/sections/relocation_section.rb
@@ -42,6 +42,7 @@ def relocation_at(n)
       #   Otherwise, the whole relocations will be returned.
       def each_relocations(&block)
         return enum_for(:each_relocations) unless block_given?
+
         Array.new(num_relocations) do |i|
           relocation_at(i).tap(&block)
         end
diff --git a/lib/elftools/sections/sym_tab_section.rb b/lib/elftools/sections/sym_tab_section.rb
index 57f1352..48a987c 100644
--- a/lib/elftools/sections/sym_tab_section.rb
+++ b/lib/elftools/sections/sym_tab_section.rb
@@ -56,6 +56,7 @@ def symbol_at(n)
       #   Otherwise return array of symbols.
       def each_symbols(&block)
         return enum_for(:each_symbols) unless block_given?
+
         Array.new(num_symbols) do |i|
           symbol_at(i).tap(&block)
         end
diff --git a/lib/elftools/structs.rb b/lib/elftools/structs.rb
index fabcfa7..6145766 100644
--- a/lib/elftools/structs.rb
+++ b/lib/elftools/structs.rb
@@ -54,6 +54,7 @@ def self_endian
         # @return [String]
         def pack(val, bytes)
           raise ArgumentError, "Not supported assign type #{val.class}" unless val.is_a?(Integer)
+
           number = val & ((1 << (8 * bytes)) - 1)
           out = []
           bytes.times do
diff --git a/lib/elftools/util.rb b/lib/elftools/util.rb
index 0fbceb7..4412db1 100644
--- a/lib/elftools/util.rb
+++ b/lib/elftools/util.rb
@@ -17,6 +17,7 @@ module ClassMethods
       def align(num, bit)
         n = 2**bit
         return num if (num % n).zero?
+
         (num + n) & ~(n - 1)
       end
 
@@ -36,6 +37,7 @@ def to_constant(mod, val)
         # if val is an integer, check if exists in mod
         if val.is_a?(Integer)
           return val if mod.constants.any? { |c| mod.const_get(c) == val }
+
           raise ArgumentError, "No constants in #{module_name} is #{val}"
         end
         val = val.to_s.upcase
@@ -43,6 +45,7 @@ def to_constant(mod, val)
         val = prefix + '_' + val unless val.start_with?(prefix)
         val = val.to_sym
         raise ArgumentError, "No constants in #{module_name} named \"#{val}\"" unless mod.const_defined?(val)
+
         mod.const_get(val)
       end
 
@@ -61,6 +64,7 @@ def cstring(stream, offset)
           c = stream.read(1)
           return nil if c.nil? # reach EOF
           break if c == "\x00"
+
           ret += c
         end
         ret