diff --git a/CHANGELOG.md b/CHANGELOG.md
index cad208aa81..678c2bb507 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,8 @@
 
 ## master (unreleased)
 
+## 1.8.1 (2020-09-19)
+
 ### Bug fixes
 
 * [#164](https://github.com/rubocop-hq/rubocop-performance/pull/164): Fix an error for `Performance/CollectionLiteralInLoop` when a method from `Enumerable` is called with no receiver. ([@eugeneius][])
diff --git a/docs/antora.yml b/docs/antora.yml
index 8029079a95..0f41da11f9 100644
--- a/docs/antora.yml
+++ b/docs/antora.yml
@@ -2,6 +2,6 @@ name: rubocop-performance
 title: RuboCop Performance
 # We always provide version without patch here (e.g. 1.1),
 # as patch versions should not appear in the docs.
-version: master
+version: '1.8'
 nav:
   - modules/ROOT/nav.adoc
diff --git a/lib/rubocop/performance/version.rb b/lib/rubocop/performance/version.rb
index ca2b3b4bda..3e176f814d 100644
--- a/lib/rubocop/performance/version.rb
+++ b/lib/rubocop/performance/version.rb
@@ -3,7 +3,7 @@
 module RuboCop
   module Performance
     module Version
-      STRING = '1.8.0'
+      STRING = '1.8.1'
     end
   end
 end
diff --git a/relnotes/v1.8.1.md b/relnotes/v1.8.1.md
new file mode 100644
index 0000000000..4e5de8c575
--- /dev/null
+++ b/relnotes/v1.8.1.md
@@ -0,0 +1,13 @@
+### Bug fixes
+
+* [#164](https://github.com/rubocop-hq/rubocop-performance/pull/164): Fix an error for `Performance/CollectionLiteralInLoop` when a method from `Enumerable` is called with no receiver. ([@eugeneius][])
+* [#165](https://github.com/rubocop-hq/rubocop-performance/issues/165): Fix a false positive for `Performance/Sum` when using initial value argument is a variable. ([@koic][])
+
+### Changes
+
+* [#163](https://github.com/rubocop-hq/rubocop-performance/pull/163): Change `Performance/Detect` to also detect offenses when index 0 or -1 is used instead (ie. `detect{ ... }[0]`). ([@dvandersluis][])
+* [#168](https://github.com/rubocop-hq/rubocop-performance/pull/168): Extend `Performance/Sum` to register an offense for `inject(&:+)`. ([@eugeneius][])
+
+[@eugeneius]: https://github.com/eugeneius
+[@koic]: https://github.com/koic
+[@dvandersluis]: https://github.com/dvandersluis