diff --git a/lib/sass/engine.rb b/lib/sass/engine.rb

index eb3c462..92a2e9f 100644

--- a/lib/sass/engine.rb

+++ b/lib/sass/engine.rb

@@ -94,13 +94,13 @@ module Sass

     # `text`: `String`

     # : The text in the line, without any whitespace at the beginning or end.

     #

-    # `tabs`: `Fixnum`

+    # `tabs`: `Integer`

     # : The level of indentation of the line.

     #

-    # `index`: `Fixnum`

+    # `index`: `Integer`

     # : The line number in the original document.

     #

-    # `offset`: `Fixnum`

+    # `offset`: `Integer`

     # : The number of bytes in on the line that the text begins.

     #   This ends up being the number of bytes of leading whitespace.

     #

diff --git a/lib/sass/error.rb b/lib/sass/error.rb

index 319ff12..f4763a9 100644

--- a/lib/sass/error.rb

+++ b/lib/sass/error.rb

@@ -69,14 +69,14 @@ module Sass

     # The name of the mixin in which the error occurred.

     # This could be `nil` if the error occurred outside a mixin.

     #

-    # @return [Fixnum]

+    # @return [String]

     def sass_mixin

       sass_backtrace.first[:mixin]

     end

     # The line of the Sass template on which the error occurred.

     #

-    # @return [Fixnum]

+    # @return [Integer]

     def sass_line

       sass_backtrace.first[:line]

     end

@@ -153,7 +153,7 @@ module Sass

       # Returns an error report for an exception in CSS format.

       #

       # @param e [Exception]

-      # @param line_offset [Fixnum] The number of the first line of the Sass template.

+      # @param line_offset [Integer] The number of the first line of the Sass template.

       # @return [String] The error report

       # @raise [Exception] `e`, if the

       #   {file:SASS_REFERENCE.md#full_exception-option `:full_exception`} option

diff --git a/lib/sass/plugin/staleness_checker.rb b/lib/sass/plugin/staleness_checker.rb

index 23a9bf2..8ff1fd2 100644

--- a/lib/sass/plugin/staleness_checker.rb

+++ b/lib/sass/plugin/staleness_checker.rb

@@ -72,7 +72,7 @@ module Sass

       # Returns whether a Sass or SCSS stylesheet has been modified since a given time.

       #

       # @param template_file [String] The location of the Sass or SCSS template.

-      # @param mtime [Fixnum] The modification time to check against.

+      # @param mtime [Time] The modification time to check against.

       # @param importer [Sass::Importers::Base] The importer used to locate the stylesheet.

       #   Defaults to the filesystem importer.

       # @return [Boolean] Whether the stylesheet has been modified.

@@ -103,7 +103,7 @@ module Sass

       # so it's better to use when checking multiple stylesheets at once.

       #

       # @param template_file [String] The location of the Sass or SCSS template.

-      # @param mtime [Fixnum] The modification time to check against.

+      # @param mtime [Time] The modification time to check against.

       # @param importer [Sass::Importers::Base] The importer used to locate the stylesheet.

       #   Defaults to the filesystem importer.

       # @return [Boolean] Whether the stylesheet has been modified.

diff --git a/lib/sass/script.rb b/lib/sass/script.rb

index 5ca639d..315094e 100644

--- a/lib/sass/script.rb

+++ b/lib/sass/script.rb

@@ -16,9 +16,9 @@ module Sass

     # Parses a string of SassScript

     #

     # @param value [String] The SassScript

-    # @param line [Fixnum] The number of the line on which the SassScript appeared.

+    # @param line [Integer] The number of the line on which the SassScript appeared.

     #   Used for error reporting

-    # @param offset [Fixnum] The number of characters in on `line` that the SassScript started.

+    # @param offset [Integer] The number of characters in on `line` that the SassScript started.

     #   Used for error reporting

     # @param options [{Symbol => Object}] An options hash;

     #   see {file:SASS_REFERENCE.md#sass_options the Sass options documentation}

diff --git a/lib/sass/script/functions.rb b/lib/sass/script/functions.rb

index 7598c20..76f8714 100644

--- a/lib/sass/script/functions.rb

+++ b/lib/sass/script/functions.rb

@@ -431,8 +431,8 @@ module Sass::Script

     # If no signatures match, the first signature is returned for error messaging.

     #

     # @param method_name [Symbol] The name of the Ruby function to be called.

-    # @param arg_arity [Fixnum] The number of unnamed arguments the function was passed.

-    # @param kwarg_arity [Fixnum] The number of keyword arguments the function was passed.

+    # @param arg_arity [Integer] The number of unnamed arguments the function was passed.

+    # @param kwarg_arity [Integer] The number of keyword arguments the function was passed.

     #

     # @return [{Symbol => Object}, nil]

     #   The signature options for the matching signature,

diff --git a/lib/sass/script/lexer.rb b/lib/sass/script/lexer.rb

index 2d7fceb..8ba3870 100644

--- a/lib/sass/script/lexer.rb

+++ b/lib/sass/script/lexer.rb

@@ -19,13 +19,13 @@ module Sass

       # `source_range`: \[`Sass::Source::Range`\]

       # : The range in the source file in which the token appeared.

       #

-      # `pos`: \[`Fixnum`\]

+      # `pos`: \[`Integer`\]

       # : The scanner position at which the SassScript token appeared.

       Token = Struct.new(:type, :value, :source_range, :pos)

       # The line number of the lexer's current position.

       #

-      # @return [Fixnum]

+      # @return [Integer]

       def line

         return @line unless @tok

         @tok.source_range.start_pos.line

@@ -34,7 +34,7 @@ module Sass

       # The number of bytes into the current line

       # of the lexer's current position (1-based).

       #

-      # @return [Fixnum]

+      # @return [Integer]

       def offset

         return @offset unless @tok

         @tok.source_range.start_pos.offset

@@ -142,9 +142,9 @@ module Sass

       }

       # @param str [String, StringScanner] The source text to lex

-      # @param line [Fixnum] The 1-based line on which the SassScript appears.

+      # @param line [Integer] The 1-based line on which the SassScript appears.

       #   Used for error reporting and sourcemap building

-      # @param offset [Fixnum] The 1-based character (not byte) offset in the line in the source.

+      # @param offset [Integer] The 1-based character (not byte) offset in the line in the source.

       #   Used for error reporting and sourcemap building

       # @param options [{Symbol => Object}] An options hash;

       #   see {file:SASS_REFERENCE.md#sass_options the Sass options documentation}

diff --git a/lib/sass/script/parser.rb b/lib/sass/script/parser.rb

index 01f2861..c44ff5d 100644

--- a/lib/sass/script/parser.rb

+++ b/lib/sass/script/parser.rb

@@ -8,22 +8,22 @@ module Sass

     class Parser

       # The line number of the parser's current position.

       #

-      # @return [Fixnum]

+      # @return [Integer]

       def line

         @lexer.line

       end

       # The column number of the parser's current position.

       #

-      # @return [Fixnum]

+      # @return [Integer]

       def offset

         @lexer.offset

       end

       # @param str [String, StringScanner] The source text to parse

-      # @param line [Fixnum] The line on which the SassScript appears.

+      # @param line [Integer] The line on which the SassScript appears.

       #   Used for error reporting and sourcemap building

-      # @param offset [Fixnum] The character (not byte) offset where the script starts in the line.

+      # @param offset [Integer] The character (not byte) offset where the script starts in the line.

       #   Used for error reporting and sourcemap building

       # @param options [{Symbol => Object}] An options hash; see

       #   {file:SASS_REFERENCE.md#sass_options the Sass options documentation}.

diff --git a/lib/sass/script/tree/node.rb b/lib/sass/script/tree/node.rb

index 2bc4e42..1e31bec 100644

--- a/lib/sass/script/tree/node.rb

+++ b/lib/sass/script/tree/node.rb

@@ -10,7 +10,7 @@ module Sass::Script::Tree

     # The line of the document on which this node appeared.

     #

-    # @return [Fixnum]

+    # @return [Integer]

     attr_accessor :line

     # The source range in the document on which this node appeared.

diff --git a/lib/sass/script/value/base.rb b/lib/sass/script/value/base.rb

index 51094e1..67a12e1 100644

--- a/lib/sass/script/value/base.rb

+++ b/lib/sass/script/value/base.rb

@@ -149,7 +149,7 @@ MSG

     # Returns the hash code of this value. Two objects' hash codes should be

     # equal if the objects are equal.

     #

-    # @return [Fixnum] The hash code.

+    # @return [Integer for Ruby 2.4.0+, Fixnum for earlier Ruby versions] The hash code.

     def hash

       value.hash

     end

@@ -176,7 +176,7 @@ MSG

       eq(other).to_bool

     end

-    # @return [Fixnum] The integer value of this value

+    # @return [Integer] The integer value of this value

     # @raise [Sass::SyntaxError] if this value isn't an integer

     def to_i

       raise Sass::SyntaxError.new("#{inspect} is not an integer.")

diff --git a/lib/sass/script/value/color.rb b/lib/sass/script/value/color.rb

index 5f12ca3..dabda4c 100644

--- a/lib/sass/script/value/color.rb

+++ b/lib/sass/script/value/color.rb

@@ -17,8 +17,8 @@ module Sass::Script::Value

     # @private

     #

     # Convert a ruby integer to a rgba components

-    # @param color [Fixnum]

-    # @return [Array<Fixnum>] Array of 4 numbers representing r,g,b and alpha

+    # @param color [Integer]

+    # @return [Array<Integer>] Array of 4 numbers representing r,g,b and alpha

     def self.int_to_rgba(color)

       rgba = (0..3).map {|n| color >> (n << 3) & 0xff}.reverse

       rgba[-1] = rgba[-1] / 255.0

@@ -293,7 +293,7 @@ module Sass::Script::Value

     # The red component of the color.

     #

-    # @return [Fixnum]

+    # @return [Integer]

     def red

       hsl_to_rgb!

       @attrs[:red]

@@ -301,7 +301,7 @@ module Sass::Script::Value

     # The green component of the color.

     #

-    # @return [Fixnum]

+    # @return [Integer]

     def green

       hsl_to_rgb!

       @attrs[:green]

@@ -309,7 +309,7 @@ module Sass::Script::Value

     # The blue component of the color.

     #

-    # @return [Fixnum]

+    # @return [Integer]

     def blue

       hsl_to_rgb!

       @attrs[:blue]

@@ -342,7 +342,7 @@ module Sass::Script::Value

     # The alpha channel (opacity) of the color.

     # This is 1 unless otherwise defined.

     #

-    # @return [Fixnum]

+    # @return [Integer]

     def alpha

       @attrs[:alpha].to_f

     end

@@ -357,7 +357,7 @@ module Sass::Script::Value

     # Returns the red, green, and blue components of the color.

     #

-    # @return [Array<Fixnum>] A frozen three-element array of the red, green, and blue

+    # @return [Array<Integer>] A frozen three-element array of the red, green, and blue

     #   values (respectively) of the color

     def rgb

       [red, green, blue].freeze

@@ -365,7 +365,7 @@ module Sass::Script::Value

     # Returns the red, green, blue, and alpha components of the color.

     #

-    # @return [Array<Fixnum>] A frozen four-element array of the red, green,

+    # @return [Array<Integer>] A frozen four-element array of the red, green,

     #   blue, and alpha values (respectively) of the color

     def rgba

       [red, green, blue, alpha].freeze

@@ -373,7 +373,7 @@ module Sass::Script::Value

     # Returns the hue, saturation, and lightness components of the color.

     #

-    # @return [Array<Fixnum>] A frozen three-element array of the

+    # @return [Array<Integer>] A frozen three-element array of the

     #   hue, saturation, and lightness values (respectively) of the color

     def hsl

       [hue, saturation, lightness].freeze

@@ -381,7 +381,7 @@ module Sass::Script::Value

     # Returns the hue, saturation, lightness, and alpha components of the color.

     #

-    # @return [Array<Fixnum>] A frozen four-element array of the hue,

+    # @return [Array<Integer>] A frozen four-element array of the hue,

     #   saturation, lightness, and alpha values (respectively) of the color

     def hsla

       [hue, saturation, lightness, alpha].freeze

diff --git a/lib/sass/script/value/number.rb b/lib/sass/script/value/number.rb

index e491c2c..6523171 100644

--- a/lib/sass/script/value/number.rb

+++ b/lib/sass/script/value/number.rb

@@ -304,7 +304,7 @@ module Sass::Script::Value

     end

     alias_method :to_sass, :inspect

-    # @return [Fixnum] The integer value of the number

+    # @return [Integer] The integer value of the number

     # @raise [Sass::SyntaxError] if the number isn't an integer

     def to_i

       super unless int?

diff --git a/lib/sass/scss/parser.rb b/lib/sass/scss/parser.rb

index efec35e..beb82f0 100644

--- a/lib/sass/scss/parser.rb

+++ b/lib/sass/scss/parser.rb

@@ -16,9 +16,9 @@ module Sass

       #   warnings and source maps.

       # @param importer [Sass::Importers::Base] The importer used to import the

       #   file being parsed. Used for source maps.

-      # @param line [Fixnum] The 1-based line on which the source string appeared,

+      # @param line [Integer] The 1-based line on which the source string appeared,

       #   if it's part of another document.

-      # @param offset [Fixnum] The 1-based character (not byte) offset in the line on

+      # @param offset [Integer] The 1-based character (not byte) offset in the line on

       #   which the source string starts. Used for error reporting and sourcemap

       #   building.

       def initialize(str, filename, importer, line = 1, offset = 1)

diff --git a/lib/sass/scss/rx.rb b/lib/sass/scss/rx.rb

index f1a952f..dd9eede 100644

--- a/lib/sass/scss/rx.rb

+++ b/lib/sass/scss/rx.rb

@@ -40,7 +40,7 @@ module Sass

       # escaping all significant characters.

       #

       # @param str [String] The text of the regexp

-      # @param flags [Fixnum] Flags for the created regular expression

+      # @param flags [Integer] Flags for the created regular expression

       # @return [Regexp]

       # @private

       def self.quote(str, flags = 0)

diff --git a/lib/sass/selector/abstract_sequence.rb b/lib/sass/selector/abstract_sequence.rb

index ef78909..a18a79f 100644

--- a/lib/sass/selector/abstract_sequence.rb

+++ b/lib/sass/selector/abstract_sequence.rb

@@ -8,7 +8,7 @@ module Sass

     class AbstractSequence

       # The line of the Sass template on which this selector was declared.

       #

-      # @return [Fixnum]

+      # @return [Integer]

       attr_reader :line

       # The name of the file in which this selector was declared.

@@ -19,8 +19,8 @@ module Sass

       # Sets the line of the Sass template on which this selector was declared.

       # This also sets the line for all child selectors.

       #

-      # @param line [Fixnum]

-      # @return [Fixnum]

+      # @param line [Integer]

+      # @return [Integer]

       def line=(line)

         members.each {|m| m.line = line}

         @line = line

@@ -42,7 +42,7 @@ module Sass

       # Subclasses should define `#_hash` rather than overriding this method,

       # which automatically handles memoizing the result.

       #

-      # @return [Fixnum]

+      # @return [Integer]

       def hash

         @_hash ||= _hash

       end

@@ -83,7 +83,7 @@ module Sass

       # The base is given by {Sass::Selector::SPECIFICITY_BASE}. This can be a

       # number or a range representing possible specificities.

       #

-      # @return [Fixnum, Range]

+      # @return [Integer, Range]

       def specificity

         _specificity(members)

       end

diff --git a/lib/sass/selector/sequence.rb b/lib/sass/selector/sequence.rb

index 0abd930..3b51ea1 100644

--- a/lib/sass/selector/sequence.rb

+++ b/lib/sass/selector/sequence.rb

@@ -6,8 +6,8 @@ module Sass

       # Sets the line of the Sass template on which this selector was declared.

       # This also sets the line for all child selectors.

       #

-      # @param line [Fixnum]

-      # @return [Fixnum]

+      # @param line [Integer]

+      # @return [Integer]

       def line=(line)

         members.each {|m| m.line = line if m.is_a?(SimpleSequence)}

         @line = line

diff --git a/lib/sass/selector/simple.rb b/lib/sass/selector/simple.rb

index df286f3..7d267d4 100644

--- a/lib/sass/selector/simple.rb

+++ b/lib/sass/selector/simple.rb

@@ -5,7 +5,7 @@ module Sass

     class Simple

       # The line of the Sass template on which this selector was declared.

       #

-      # @return [Fixnum]

+      # @return [Integer]

       attr_accessor :line

       # The name of the file in which this selector was declared,

@@ -36,7 +36,7 @@ module Sass

       # so if that contains information irrelevant to the identity of the selector,

       # this should be overridden.

       #

-      # @return [Fixnum]

+      # @return [Integer]

       def hash

         @_hash ||= equality_key.hash

       end

diff --git a/lib/sass/shared.rb b/lib/sass/shared.rb

index 9e9189c..1f50995 100644

--- a/lib/sass/shared.rb

+++ b/lib/sass/shared.rb

@@ -31,7 +31,7 @@ module Sass

     #   A `Fixnum` in 1.8, a `String` in 1.9

     # @param finish [Character] The character closing the balanced pair.

     #   A `Fixnum` in 1.8, a `String` in 1.9

-    # @param count [Fixnum] The number of opening characters matched

+    # @param count [Integer] The number of opening characters matched

     #   before calling this method

     # @return [(String, String)] The string matched within the balanced pair

     #   and the rest of the string.

diff --git a/lib/sass/source/map.rb b/lib/sass/source/map.rb

index fdad539..b51c7c6 100644

--- a/lib/sass/source/map.rb

+++ b/lib/sass/source/map.rb

@@ -37,7 +37,7 @@ module Sass::Source

     # Shifts all output source ranges forward one or more lines.

     #

-    # @param delta [Fixnum] The number of lines to shift the ranges forward.

+    # @param delta [Integer] The number of lines to shift the ranges forward.

     def shift_output_lines(delta)

       return if delta == 0

       @data.each do |m|

@@ -49,7 +49,7 @@ module Sass::Source

     # Shifts any output source ranges that lie on the first line forward one or

     # more characters on that line.

     #

-    # @param delta [Fixnum] The number of characters to shift the ranges

+    # @param delta [Integer] The number of characters to shift the ranges

     #   forward.

     def shift_output_offsets(delta)

       return if delta == 0

diff --git a/lib/sass/source/position.rb b/lib/sass/source/position.rb

index df39bd3..a62af45 100644

--- a/lib/sass/source/position.rb

+++ b/lib/sass/source/position.rb

@@ -2,17 +2,17 @@ module Sass::Source

   class Position

     # The one-based line of the document associated with the position.

     #

-    # @return [Fixnum]

+    # @return [Integer]

     attr_accessor :line

     # The one-based offset in the line of the document associated with the

     # position.

     #

-    # @return [Fixnum]

+    # @return [Integer]

     attr_accessor :offset

-    # @param line [Fixnum] The source line

-    # @param offset [Fixnum] The source offset

+    # @param line [Integer] The source line

+    # @param offset [Integer] The source offset

     def initialize(line, offset)

       @line = line

       @offset = offset

diff --git a/lib/sass/tree/comment_node.rb b/lib/sass/tree/comment_node.rb

index 8b7cdf0..1b73a15 100644

--- a/lib/sass/tree/comment_node.rb

+++ b/lib/sass/tree/comment_node.rb

@@ -59,7 +59,7 @@ module Sass::Tree

     # Returns the number of lines in the comment.

     #

-    # @return [Fixnum]

+    # @return [Integer]

     def lines

       @value.inject(0) do |s, e|

         next s + e.count("\n") if e.is_a?(String)

diff --git a/lib/sass/tree/node.rb b/lib/sass/tree/node.rb

index 3d8c444..8703bc4 100644

--- a/lib/sass/tree/node.rb

+++ b/lib/sass/tree/node.rb

@@ -69,7 +69,7 @@ module Sass

       # The line of the document on which this node appeared.

       #

-      # @return [Fixnum]

+      # @return [Integer]

       attr_accessor :line

       # The source range in the document on which this node appeared.

diff --git a/lib/sass/tree/prop_node.rb b/lib/sass/tree/prop_node.rb

index bef8c59..d26c824 100644

--- a/lib/sass/tree/prop_node.rb

+++ b/lib/sass/tree/prop_node.rb

@@ -39,7 +39,7 @@ module Sass::Tree

     # * This is a child property of another property

     # * The parent property has a value, and thus will be rendered

     #

-    # @return [Fixnum]

+    # @return [Integer]

     attr_accessor :tabs

     # The source range in which the property name appears.

diff --git a/lib/sass/tree/rule_node.rb b/lib/sass/tree/rule_node.rb

index 46bd8ac..dabf772 100644

--- a/lib/sass/tree/rule_node.rb

+++ b/lib/sass/tree/rule_node.rb

@@ -40,7 +40,7 @@ module Sass::Tree

     # * This is a child rule of another rule

     # * The parent rule has properties, and thus will be rendered

     #

-    # @return [Fixnum]

+    # @return [Integer]

     attr_accessor :tabs

     # The entire selector source range for this rule.

diff --git a/lib/sass/util.rb b/lib/sass/util.rb

index 0a80fc7..e67500f 100644

--- a/lib/sass/util.rb

+++ b/lib/sass/util.rb

@@ -418,7 +418,7 @@ module Sass

     # Returns information about the caller of the previous method.

     #

     # @param entry [String] An entry in the `#caller` list, or a similarly formatted string

-    # @return [[String, Fixnum, (String, nil)]]

+    # @return [[String, Integer, (String, nil)]]

     #   An array containing the filename, line, and method name of the caller.

     #   The method name may be nil

     def caller_info(entry = nil)

@@ -636,7 +636,7 @@ module Sass

     # Returns an array of ints representing the JRuby version number.

     #

-    # @return [Array<Fixnum>]

+    # @return [Array<Integer>]

     def jruby_version

       @jruby_version ||= ::JRUBY_VERSION.split(".").map {|s| s.to_i}

     end

@@ -941,7 +941,7 @@ module Sass

     # A version of `Enumerable#enum_cons` that works in Ruby 1.8 and 1.9.

     #

     # @param enum [Enumerable] The enumerable to get the enumerator for

-    # @param n [Fixnum] The size of each cons

+    # @param n [Integer] The size of each cons

     # @return [Enumerator] The consed enumerator

     def enum_cons(enum, n)

       ruby1_8? ? enum.enum_cons(n) : enum.each_cons(n)

@@ -950,7 +950,7 @@ module Sass

     # A version of `Enumerable#enum_slice` that works in Ruby 1.8 and 1.9.

     #

     # @param enum [Enumerable] The enumerable to get the enumerator for

-    # @param n [Fixnum] The size of each slice

+    # @param n [Integer] The size of each slice

     # @return [Enumerator] The consed enumerator

     def enum_slice(enum, n)

       ruby1_8? ? enum.enum_slice(n) : enum.each_slice(n)

@@ -977,7 +977,7 @@ module Sass

     # Returns the ASCII code of the given character.

     #

     # @param c [String] All characters but the first are ignored.

-    # @return [Fixnum] The ASCII code of `c`.

+    # @return [Integer] The ASCII code of `c`.

     def ord(c)

       ruby1_8? ? c[0] : c.ord

     end

@@ -1102,11 +1102,11 @@ module Sass

     # Converts the argument into a valid JSON value.

     #

-    # @param v [Fixnum, String, Array, Boolean, nil]

+    # @param v [Integer, String, Array, Boolean, nil]

     # @return [String]

     def json_value_of(v)

       case v

-      when Fixnum

+      when Integer

         v.to_s

       when String

         "\"" + json_escape_string(v) + "\""

@@ -1139,7 +1139,7 @@ module Sass

     # Encodes `value` as VLQ (http://en.wikipedia.org/wiki/VLQ).

     #

-    # @param value [Fixnum]

+    # @param value [Integer]

     # @return [String] The encoded value

     def encode_vlq(value)

       if value < 0

diff --git a/lib/sass/version.rb b/lib/sass/version.rb

index 89c8a06..3aa0064 100644

--- a/lib/sass/version.rb

+++ b/lib/sass/version.rb

@@ -8,7 +8,7 @@ module Sass

   # if it was installed from Git.

   module Version

     # Returns a hash representing the version of Sass.

-    # The `:major`, `:minor`, and `:teeny` keys have their respective numbers as Fixnums.

+    # The `:major`, `:minor`, and `:teeny` keys have their respective numbers as Integers.

     # The `:name` key has the name of the version.

     # The `:string` key contains a human-readable string representation of the version.

     # The `:number` key is the major, minor, and teeny keys separated by periods.

@@ -41,7 +41,7 @@ module Sass

     #       :prerelease_number => 1

     #     }

     #

-    # @return [{Symbol => String/Fixnum}] The version hash

+    # @return [{Symbol => String/Integer}] The version hash

     # @comment

     #   rubocop:disable ClassVars

     def version