diff --git a/CHANGELOG.md b/CHANGELOG.md
index 45005c194..979b71bea 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,10 @@
 
 ## master (unreleased)
 
+### New features
+
+* [#49](https://github.com/rubocop-hq/rubocop-ast/pull/49): Add `DefNode#endless?` (Ruby 3.0). ([@marcandre][])
+
 ## 0.7.1 (2020-09-28)
 
 ### Bug fixes
diff --git a/lib/rubocop/ast/node/def_node.rb b/lib/rubocop/ast/node/def_node.rb
index 4769acc6d..96a61d631 100644
--- a/lib/rubocop/ast/node/def_node.rb
+++ b/lib/rubocop/ast/node/def_node.rb
@@ -58,6 +58,11 @@ def body
       def receiver
         children[-4]
       end
+
+      # @return [Boolean] if the definition is without an `end` or not.
+      def endless?
+        !loc.end
+      end
     end
   end
 end
diff --git a/spec/rubocop/ast/def_node_spec.rb b/spec/rubocop/ast/def_node_spec.rb
index 3aba8082e..af76b5be0 100644
--- a/spec/rubocop/ast/def_node_spec.rb
+++ b/spec/rubocop/ast/def_node_spec.rb
@@ -516,4 +516,18 @@
       it { expect(def_node.body.begin_type?).to be(true) }
     end
   end
+
+  describe '#endless?' do
+    context 'with standard method definition' do
+      let(:source) { 'def foo; 42; end' }
+
+      it { expect(def_node.endless?).to be(false) }
+    end
+
+    context 'with endless method definition', :ruby30 do
+      let(:source) { 'def foo() = 42' }
+
+      it { expect(def_node.endless?).to be(true) }
+    end
+  end
 end
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index b672dd26c..56cac2e75 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -34,6 +34,10 @@
   let(:ruby_version) { 2.7 }
 end
 
+RSpec.shared_context 'ruby 3.0', :ruby30 do
+  let(:ruby_version) { 3.0 }
+end
+
 # ...
 module DefaultRubyVersion
   extend RSpec::SharedContext