diff --git a/lib/active_fedora/noid.rb b/lib/active_fedora/noid.rb
index ffdf32f..73cb484 100644
--- a/lib/active_fedora/noid.rb
+++ b/lib/active_fedora/noid.rb
@@ -17,6 +17,7 @@ def config
       end
 
       def treeify(identifier)
+        raise ArgumentError, 'Identifier must be a string of size > 0 in order to be treeified' if identifier.blank?
         head = identifier.split('/').first
         head.gsub!(/#.*/, '')
         (head.scan(/..?/).first(4) + [identifier]).join('/')
diff --git a/spec/unit/noid_spec.rb b/spec/unit/noid_spec.rb
index e314c7f..68e4ae2 100644
--- a/spec/unit/noid_spec.rb
+++ b/spec/unit/noid_spec.rb
@@ -18,5 +18,17 @@
       let(:id) { 'abc123z' }
       it { is_expected.to eq 'ab/c1/23/z/abc123z' }
     end
+    context 'with an empty string' do
+      let(:id) { '' }
+      it 'raises ArgumentError' do
+        expect { subject }.to raise_error(ArgumentError)
+      end
+    end
+    context 'with a nil' do
+      let(:id) { nil }
+      it 'raises ArgumentError' do
+        expect { subject }.to raise_error(ArgumentError)
+      end
+    end
   end
 end