diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index 7af7b50..59b138a 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -2564,7 +2564,7 @@
         }
 
         /* UTF-16 code pair: */
-        if (q >= e) {
+        if (e - q < 2) {
             errmsg = "unexpected end of data";
             startinpos = (((const char *)q)-2)-starts;
             endinpos = ((const char *)e)-starts;