diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index 670fca4..48821bd 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -368,7 +368,7 @@
 	register Py_UNICODE *u;
 	register int i;
 	u = PyUnicode_AS_UNICODE(unicode);
-	for (i = size; i >= 0; i--)
+	for (i = size; i > 0; i--)
 	    *u++ = *w++;
     }
 #endif
@@ -393,7 +393,7 @@
 	register Py_UNICODE *u;
 	register int i;
 	u = PyUnicode_AS_UNICODE(unicode);
-	for (i = size; i >= 0; i--)
+	for (i = size; i > 0; i--)
 	    *w++ = *u++;
     }
 #endif