diff --git a/CHANGELOG.md b/CHANGELOG.md
index af22dcb4e..b27266535 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,9 @@
 
 ## master (unreleased)
 
+### Bug fixes
+* [#115](https://github.com/rubocop-hq/rubocop-ast/pull/115): Fix `ConstNode#absolute?` when the constant is not namespaced. ([@dvandersluis][])
+
 ## 0.4.0 (2020-09-11)
 
 ### New features
@@ -97,3 +100,4 @@
 [@owst]: https://github.com/owst
 [@fatkodima]: https://github.com/fatkodima
 [@koic]: https://github.com/koic
+[@dvandersluis]: https://github.com/dvandersluis
diff --git a/lib/rubocop/ast/node/const_node.rb b/lib/rubocop/ast/node/const_node.rb
index 12f52e01d..eba9e4f3d 100644
--- a/lib/rubocop/ast/node/const_node.rb
+++ b/lib/rubocop/ast/node/const_node.rb
@@ -28,6 +28,8 @@ def module_name?
 
       # @return [Boolean] if the constant starts with `::` (aka s(:cbase))
       def absolute?
+        return false unless namespace
+
         each_path.first.cbase_type?
       end
 
diff --git a/spec/rubocop/ast/const_node_spec.rb b/spec/rubocop/ast/const_node_spec.rb
index 8a53db0f9..57d8f8553 100644
--- a/spec/rubocop/ast/const_node_spec.rb
+++ b/spec/rubocop/ast/const_node_spec.rb
@@ -31,6 +31,20 @@
 
       it { expect(const_node.absolute?).to eq false }
     end
+
+    context 'with a non-namespaced constant' do
+      let(:source) { 'Foo' }
+
+      it { expect(const_node.absolute?).to eq false }
+    end
+  end
+
+  describe '#relative?' do
+    context 'with a non-namespaced constant' do
+      let(:source) { 'Foo' }
+
+      it { expect(const_node.relative?).to eq true }
+    end
   end
 
   describe '#each_path' do