diff --git a/CHANGELOG.md b/CHANGELOG.md
index 098044809fb..7878f11ff78 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,10 @@
 * [#8299](https://github.com/rubocop-hq/rubocop/issues/8299): Fix an incorrect auto-correct for `Style/RedundantCondition` when using `raise`, `rescue`, or `and` without argument parentheses in `else`. ([@koic][])
 * [#8335](https://github.com/rubocop-hq/rubocop/issues/8335): Fix incorrect character class detection for nested or POSIX bracket character classes in `Style/RedundantRegexpEscape`. ([@owst][])
 
+### Changes
+
+* [#8350](https://github.com/rubocop-hq/rubocop/pull/8350): Set default max line length to 120 for `Style/MultilineMethodSignature`. ([@koic][])
+
 ## 0.88.0 (2020-07-13)
 
 ### New features
diff --git a/lib/rubocop/cop/style/multiline_method_signature.rb b/lib/rubocop/cop/style/multiline_method_signature.rb
index 72fa31d92ab..78d0888db01 100644
--- a/lib/rubocop/cop/style/multiline_method_signature.rb
+++ b/lib/rubocop/cop/style/multiline_method_signature.rb
@@ -53,7 +53,7 @@ def definition_width(node)
         end
 
         def max_line_length
-          config.for_cop('Layout/LineLength')['Max'] || 80
+          config.for_cop('Layout/LineLength')['Max'] || 120
         end
       end
     end