diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index 7e455a5e328..9937705eef1 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -427,7 +427,7 @@ PyObject *PyUnicode_FromString(const char *u)
 	}
     }
 
-    unicode = _PyUnicode_New(size);
+    unicode = _PyUnicode_New(size+1);
     if (!unicode)
         return NULL;