diff --git a/.rubocop.yml b/.rubocop.yml
index 1061de7c7978afdf5c89b4b77b1e574bf338638e..6e8f599bf25623c111467da2e27172ff4263dbdc 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -572,6 +572,10 @@ Lint/ElseLayout:
 Lint/EmptyEnsure:
   Enabled: true
 
+# Checks for the presence of `when` branches without a body.
+Lint/EmptyWhen:
+  Enabled: true
+
 # Align ends correctly.
 Lint/EndAlignment:
   Enabled: true
diff --git a/.rubocop_todo.yml b/.rubocop_todo.yml
index 7ef5523de4b55eaa152c9b4903e4ec1702ce9680..648b3fc49d2d08d420a9c5ddb5300e551216dc36 100644
--- a/.rubocop_todo.yml
+++ b/.rubocop_todo.yml
@@ -21,10 +21,6 @@ Lint/AmbiguousRegexpLiteral:
 Lint/AssignmentInCondition:
   Enabled: false
 
-# Offense count: 1
-Lint/EmptyWhen:
-  Enabled: false
-
 # Offense count: 20
 Lint/HandleExceptions:
   Enabled: false
diff --git a/lib/gitlab/diff/parser.rb b/lib/gitlab/diff/parser.rb
index 59a2367b65d2b01d2e9394e0e3d4302e01c701a9..89320f5d9dc4342bb3266a1ec6c603bf29ed4b9e 100644
--- a/lib/gitlab/diff/parser.rb
+++ b/lib/gitlab/diff/parser.rb
@@ -45,7 +45,7 @@ module Gitlab
               line_new += 1
             when "-"
               line_old += 1
-            when "\\"
+            when "\\" # rubocop:disable Lint/EmptyWhen
               # No increment
             else
               line_new += 1