diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 3b85970a6..1568c311b 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -10,7 +10,7 @@ jobs:
     name: Base steps
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
     - name: Check Whitespace
       run: git diff --check -- HEAD~1
   ruby-spec:
@@ -23,7 +23,7 @@ jobs:
         ruby: [ruby-2.7, ruby-3.0, ruby-3.1]
         os: [macos-latest, ubuntu-latest]
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
     - uses: ruby/setup-ruby@v1
       with:
         ruby-version: ${{ matrix.ruby }}
@@ -39,7 +39,7 @@ jobs:
         ruby: [ruby-2.7, ruby-3.0, ruby-3.1]
         os: [macos-latest, ubuntu-latest]
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
       with:
         fetch-depth: 0
     - uses: ruby/setup-ruby@v1
@@ -57,7 +57,7 @@ jobs:
         ruby: [ruby-2.7, ruby-3.0, ruby-3.1]
         os: [macos-latest, ubuntu-latest]
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
     - uses: ruby/setup-ruby@v1
       with:
         ruby-version: ${{ matrix.ruby }}
@@ -77,7 +77,7 @@ jobs:
         ruby: [ruby-2.7, ruby-3.0, ruby-3.1]
         os: [macos-latest, ubuntu-latest]
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
     - uses: ruby/setup-ruby@v1
       with:
         ruby-version: ${{ matrix.ruby }}
@@ -93,7 +93,7 @@ jobs:
         ruby: [ruby-2.7, ruby-3.0, ruby-3.1]
         os: [macos-latest, ubuntu-latest]
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
     - uses: ruby/setup-ruby@v1
       with:
         ruby-version: ${{ matrix.ruby }}
@@ -109,7 +109,7 @@ jobs:
         ruby: [ruby-2.7, ruby-3.0, ruby-3.1]
         os: [macos-latest, ubuntu-latest]
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
     - uses: ruby/setup-ruby@v1
       with:
         ruby-version: ${{ matrix.ruby }}
@@ -125,7 +125,7 @@ jobs:
         ruby: [ruby-2.7, ruby-3.0, ruby-3.1]
         os: [macos-latest, ubuntu-latest]
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
     - uses: ruby/setup-ruby@v1
       with:
         ruby-version: ${{ matrix.ruby }}
diff --git a/Changelog.md b/Changelog.md
index a164246a7..9290058ed 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -1,3 +1,9 @@
+# v0.11.6 2022-04-10
+
+* [#1317](https://github.com/mbj/mutant/pull/1317)
+
+  Fix forward arg mutations.
+
 # v0.11.5 2022-04-03
 
 * [#1314](https://github.com/mbj/mutant/pull/1314)
diff --git a/Gemfile.lock b/Gemfile.lock
index ee49a8a33..59e1ff269 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    mutant (0.11.5)
+    mutant (0.11.6)
       diff-lcs (~> 1.3)
       parser (~> 3.1.0)
       regexp_parser (~> 2.0, >= 2.0.3)
diff --git a/foo.rb b/foo.rb
deleted file mode 100644
index fcad1d9a1..000000000
--- a/foo.rb
+++ /dev/null
@@ -1,5 +0,0 @@
-# frozen_string_literal: true
-
-def verses(first_verse, last_verse)
-  first_verse.downto(last_verse).map { verse(_1) }.join("\n")
-end
diff --git a/lib/mutant/mutation.rb b/lib/mutant/mutation.rb
index 608c25385..34971e33c 100644
--- a/lib/mutant/mutation.rb
+++ b/lib/mutant/mutation.rb
@@ -7,7 +7,7 @@ class Mutation
     include Concord::Public.new(:subject, :node)
 
     CODE_DELIMITER = "\0"
-    CODE_RANGE     = (0..4).freeze
+    CODE_RANGE     = (..4).freeze
 
     # Mutation identification code
     #
diff --git a/lib/mutant/mutator/node/arguments.rb b/lib/mutant/mutator/node/arguments.rb
index 3eb689384..b7ed60357 100644
--- a/lib/mutant/mutator/node/arguments.rb
+++ b/lib/mutant/mutator/node/arguments.rb
@@ -19,17 +19,27 @@ def dispatch
         end
 
         def emit_argument_presence
-          emit_type unless removed_block_arg?(EMPTY_ARRAY)
+          emit_type unless removed_block_arg?(EMPTY_ARRAY) || forward_arg?
 
-          Util::Array::Presence.call(children).each do |children|
-            unless removed_block_arg?(children) || (children.one? && n_mlhs?(children.first))
-              emit_type(*children)
+          children.each_with_index do |removed, index|
+            new_arguments = children.dup
+            new_arguments.delete_at(index)
+            unless n_forward_arg?(removed) || removed_block_arg?(new_arguments) || only_mlhs?(new_arguments)
+              emit_type(*new_arguments)
             end
           end
         end
 
-        def removed_block_arg?(children)
-          anonymous_block_arg? && children.none?(&ANONYMOUS_BLOCKARG_PRED)
+        def only_mlhs?(new_arguments)
+          new_arguments.one? && n_mlhs?(new_arguments.first)
+        end
+
+        def forward_arg?
+          children.last && n_forward_arg?(children.last)
+        end
+
+        def removed_block_arg?(new_arguments)
+          anonymous_block_arg? && new_arguments.none?(&ANONYMOUS_BLOCKARG_PRED)
         end
 
         def anonymous_block_arg?
@@ -47,7 +57,7 @@ def emit_argument_mutations
         end
 
         def invalid_argument_replacement?(mutant, index)
-          n_arg?(mutant) && children[0...index].any?(&method(:n_optarg?))
+          n_arg?(mutant) && children[...index].any?(&method(:n_optarg?))
         end
 
         def emit_mlhs_expansion
diff --git a/lib/mutant/mutator/node/send.rb b/lib/mutant/mutator/node/send.rb
index 4632d9a64..ea75e818d 100644
--- a/lib/mutant/mutator/node/send.rb
+++ b/lib/mutant/mutator/node/send.rb
@@ -241,7 +241,9 @@ def emit_argument_propagation
 
           argument = Mutant::Util.one(arguments)
 
-          emit_propagation(argument) unless n_kwargs?(argument)
+          return if n_kwargs?(argument) || n_forwarded_args?(argument)
+
+          emit_propagation(argument)
         end
 
         def mutate_receiver
diff --git a/lib/mutant/mutator/node/send/attribute_assignment.rb b/lib/mutant/mutator/node/send/attribute_assignment.rb
index adff72a98..081622e9b 100644
--- a/lib/mutant/mutator/node/send/attribute_assignment.rb
+++ b/lib/mutant/mutator/node/send/attribute_assignment.rb
@@ -7,7 +7,7 @@ class Send
         # Mutator for attribute assignments
         class AttributeAssignment < self
 
-          ATTRIBUTE_RANGE = (0..-2).freeze
+          ATTRIBUTE_RANGE = (..-2).freeze
 
           private_constant(*constants(false))
 
diff --git a/lib/mutant/mutator/node/when.rb b/lib/mutant/mutator/node/when.rb
index bb3ebf625..979a9fc7d 100644
--- a/lib/mutant/mutator/node/when.rb
+++ b/lib/mutant/mutator/node/when.rb
@@ -22,7 +22,7 @@ def dispatch
 
         def mutate_conditions
           conditions = children.length - 1
-          children[0..-2].each_index do |index|
+          children[..-2].each_index do |index|
             delete_child(index) if conditions > 1
             mutate_child(index)
           end
diff --git a/lib/mutant/version.rb b/lib/mutant/version.rb
index 340d97db8..6a930fa2d 100644
--- a/lib/mutant/version.rb
+++ b/lib/mutant/version.rb
@@ -2,5 +2,5 @@
 
 module Mutant
   # Current mutant version
-  VERSION = '0.11.5'
+  VERSION = '0.11.6'
 end # Mutant
diff --git a/meta/def.rb b/meta/def.rb
index 6ca649e5f..d2ed58844 100644
--- a/meta/def.rb
+++ b/meta/def.rb
@@ -170,7 +170,6 @@
 end
 
 Mutant::Meta::Example.add :def do
-
   source 'def self.foo(a, b); end'
 
   # Deletion of each argument
@@ -188,3 +187,29 @@
   mutation 'def self.foo(a, b); raise; end'
   mutation 'def self.foo(a, b); super; end'
 end
+
+Mutant::Meta::Example.add :def do
+  source 'def foo(...); end'
+
+  mutation 'def foo(...); raise; end'
+  mutation 'def foo(...); super; end'
+end
+
+Mutant::Meta::Example.add :def do
+  source 'def foo(a, ...); end'
+
+  mutation 'def foo(_a, ...); end'
+  mutation 'def foo(a, ...); raise; end'
+  mutation 'def foo(a, ...); super; end'
+  mutation 'def foo(...); end'
+end
+
+Mutant::Meta::Example.add :def, :send do
+  source 'def foo(...); bar(...) end'
+
+  mutation 'def foo(...); bar; end'
+  mutation 'def foo(...); raise; end'
+  mutation 'def foo(...); super; end'
+  mutation 'def foo(...); nil; end'
+  mutation 'def foo(...); end'
+end
diff --git a/spec/support/xspec.rb b/spec/support/xspec.rb
index e2015a5f4..e933bee97 100644
--- a/spec/support/xspec.rb
+++ b/spec/support/xspec.rb
@@ -90,7 +90,7 @@ def self.assert_not_empty(event_list)
     private_class_method :assert_not_empty
 
     def self.assert_total(event_list)
-      return unless event_list[0..-2].map(&:first).any?(&TERMINATE_EVENTS.public_method(:include?))
+      return unless event_list[..-2].map(&:first).any?(&TERMINATE_EVENTS.public_method(:include?))
 
       fail "Reaction not total: #{event_list}"
     end
diff --git a/spec/unit/mutant/cli_spec.rb b/spec/unit/mutant/cli_spec.rb
index 7f0aec22a..6e11e1933 100644
--- a/spec/unit/mutant/cli_spec.rb
+++ b/spec/unit/mutant/cli_spec.rb
@@ -806,7 +806,7 @@ def self.main_body
 
             let(:expected_events) do
               [
-                *super()[0..-2],
+                *super()[..-2],
                 [
                   :stderr,
                   :puts,
diff --git a/spec/unit/mutant/expression/namespace/recursive_spec.rb b/spec/unit/mutant/expression/namespace/recursive_spec.rb
index f342ecc0a..1015c17d0 100644
--- a/spec/unit/mutant/expression/namespace/recursive_spec.rb
+++ b/spec/unit/mutant/expression/namespace/recursive_spec.rb
@@ -49,19 +49,19 @@
       context 'on constants' do
         let(:other) { parse_expression('TestApp::Literal::Deep') }
 
-        it { should be(input[0..-2].length) }
+        it { should be(input[..-2].length) }
       end
 
       context 'on singleton method' do
         let(:other) { parse_expression('TestApp::Literal.foo') }
 
-        it { should be(input[0..-2].length) }
+        it { should be(input[..-2].length) }
       end
 
       context 'on instance method' do
         let(:other) { parse_expression('TestApp::Literal#foo') }
 
-        it { should be(input[0..-2].length) }
+        it { should be(input[..-2].length) }
       end
     end
   end