diff --git a/inflection/__init__.py b/inflection/__init__.py
index c18a0b6..1e0b907 100644
--- a/inflection/__init__.py
+++ b/inflection/__init__.py
@@ -85,7 +85,8 @@
     'rice',
     'series',
     'sheep',
-    'species'}
+    'species',
+    'diabetes'}
 
 
 def _irregular(singular: str, plural: str) -> None: