diff --git a/Lib/inspect.py b/Lib/inspect.py
index b84aec0..45515fc 100644
--- a/Lib/inspect.py
+++ b/Lib/inspect.py
@@ -894,7 +894,7 @@
     if kwonlyargs:
         for kwonlyarg in kwonlyargs:
             spec = formatargandannotation(kwonlyarg)
-            if kwonlyarg in kwonlydefaults:
+            if kwonlydefaults and kwonlyarg in kwonlydefaults:
                 spec += formatvalue(kwonlydefaults[kwonlyarg])
             specs.append(spec)
     if varkw is not None: