diff --git a/lib/yard/tags/default_factory.rb b/lib/yard/tags/default_factory.rb
index 78bfce41e..aee61a949 100644
--- a/lib/yard/tags/default_factory.rb
+++ b/lib/yard/tags/default_factory.rb
@@ -143,6 +143,7 @@ def extract_types_and_name_from_text_unstripped(text, opening_types = TYPELIST_O
         seen_space = false
         i = 0
         last_seen = ''
+        text ||= ''
         while i < text.length
           c = text[i, 1]
 
diff --git a/spec/tags/default_factory_spec.rb b/spec/tags/default_factory_spec.rb
index 21b0398d2..743841e35 100644
--- a/spec/tags/default_factory_spec.rb
+++ b/spec/tags/default_factory_spec.rb
@@ -68,6 +68,7 @@ def parse_types(types)
     end
 
     it "returns text unparsed if there is no type list" do
+      expect(parse_types(nil)).to eq [nil, nil, '']
       expect(parse_types('')).to eq [nil, nil, '']
       expect(parse_types('[]')).to eq [nil, nil, '[]']
     end