diff --git a/Modules/_tkinter.c b/Modules/_tkinter.c
index 5095060..6e595cc 100644
--- a/Modules/_tkinter.c
+++ b/Modules/_tkinter.c
@@ -2750,7 +2750,9 @@
 		return NULL;
 
 	context.maxsize = PySequence_Size(item);
-	if (context.maxsize <= 0)
+	if (context.maxsize < 0)
+		return NULL;
+	if (context.maxsize == 0)
 		return PyTuple_New(0);
 
 	context.tuple = PyTuple_New(context.maxsize);