diff --git a/changelog/change_make_pluralization_grammar_aware_of_bytes.md b/changelog/change_make_pluralization_grammar_aware_of_bytes.md
new file mode 100644
index 0000000000..1c34bf1259
--- /dev/null
+++ b/changelog/change_make_pluralization_grammar_aware_of_bytes.md
@@ -0,0 +1 @@
+* [#1306](https://github.com/rubocop/rubocop-rails/pull/1306): Make `Rails/PluralizationGrammar` aware of byte methods. ([@earlopain][])
diff --git a/config/default.yml b/config/default.yml
index 9e0c976ba6..40c20b8edf 100644
--- a/config/default.yml
+++ b/config/default.yml
@@ -765,6 +765,7 @@ Rails/PluralizationGrammar:
   Description: 'Checks for incorrect grammar when using methods like `3.day.ago`.'
   Enabled: true
   VersionAdded: '0.35'
+  VersionChanged: '<<next>>'
 
 Rails/Presence:
   Description: 'Checks code that can be written more easily using `Object#presence` defined by Active Support.'
diff --git a/lib/rubocop/cop/rails/pluralization_grammar.rb b/lib/rubocop/cop/rails/pluralization_grammar.rb
index ef62d15c8c..d5bcdb3191 100644
--- a/lib/rubocop/cop/rails/pluralization_grammar.rb
+++ b/lib/rubocop/cop/rails/pluralization_grammar.rb
@@ -10,25 +10,38 @@ module Rails
       #   # bad
       #   3.day.ago
       #   1.months.ago
+      #   5.megabyte
+      #   1.gigabyte
       #
       #   # good
       #   3.days.ago
       #   1.month.ago
+      #   5.megabytes
+      #   1.gigabyte
       class PluralizationGrammar < Base
         extend AutoCorrector
 
-        SINGULAR_DURATION_METHODS = { second: :seconds,
-                                      minute: :minutes,
-                                      hour: :hours,
-                                      day: :days,
-                                      week: :weeks,
-                                      fortnight: :fortnights,
-                                      month: :months,
-                                      year: :years }.freeze
-
-        RESTRICT_ON_SEND = SINGULAR_DURATION_METHODS.keys + SINGULAR_DURATION_METHODS.values
-
-        PLURAL_DURATION_METHODS = SINGULAR_DURATION_METHODS.invert.freeze
+        SINGULAR_METHODS = { second: :seconds,
+                             minute: :minutes,
+                             hour: :hours,
+                             day: :days,
+                             week: :weeks,
+                             fortnight: :fortnights,
+                             month: :months,
+                             year: :years,
+                             byte: :bytes,
+                             kilobyte: :kilobytes,
+                             megabyte: :megabytes,
+                             gigabyte: :gigabytes,
+                             terabyte: :terabytes,
+                             petabyte: :petabytes,
+                             exabyte: :exabytes,
+                             zettabyte: :zettabytes }
+                           .freeze
+
+        RESTRICT_ON_SEND = SINGULAR_METHODS.keys + SINGULAR_METHODS.values
+
+        PLURAL_METHODS = SINGULAR_METHODS.invert.freeze
 
         MSG = 'Prefer `%<number>s.%<correct>s`.'
 
@@ -86,15 +99,15 @@ def literal_number?(node)
         end
 
         def pluralize(method_name)
-          SINGULAR_DURATION_METHODS.fetch(method_name.to_sym).to_s
+          SINGULAR_METHODS.fetch(method_name.to_sym).to_s
         end
 
         def singularize(method_name)
-          PLURAL_DURATION_METHODS.fetch(method_name.to_sym).to_s
+          PLURAL_METHODS.fetch(method_name.to_sym).to_s
         end
 
         def duration_method?(method_name)
-          SINGULAR_DURATION_METHODS.key?(method_name) || PLURAL_DURATION_METHODS.key?(method_name)
+          SINGULAR_METHODS.key?(method_name) || PLURAL_METHODS.key?(method_name)
         end
       end
     end
diff --git a/spec/rubocop/cop/rails/pluralization_grammar_spec.rb b/spec/rubocop/cop/rails/pluralization_grammar_spec.rb
index 65a9565336..2d4f6f8298 100644
--- a/spec/rubocop/cop/rails/pluralization_grammar_spec.rb
+++ b/spec/rubocop/cop/rails/pluralization_grammar_spec.rb
@@ -83,4 +83,12 @@
   it_behaves_like 'enforces pluralization grammar', 'fortnight'
   it_behaves_like 'enforces pluralization grammar', 'month'
   it_behaves_like 'enforces pluralization grammar', 'year'
+  it_behaves_like 'enforces pluralization grammar', 'byte'
+  it_behaves_like 'enforces pluralization grammar', 'kilobyte'
+  it_behaves_like 'enforces pluralization grammar', 'megabyte'
+  it_behaves_like 'enforces pluralization grammar', 'gigabyte'
+  it_behaves_like 'enforces pluralization grammar', 'terabyte'
+  it_behaves_like 'enforces pluralization grammar', 'petabyte'
+  it_behaves_like 'enforces pluralization grammar', 'exabyte'
+  it_behaves_like 'enforces pluralization grammar', 'zettabyte'
 end