diff --git a/Python/marshal.c b/Python/marshal.c
index eac4616..897c15e 100644
--- a/Python/marshal.c
+++ b/Python/marshal.c
@@ -1013,6 +1013,7 @@
 	RFILE rf;
 	rf.fp = fp;
 	rf.strings = NULL;
+	rf.ptr = rf.end = NULL;
 	return r_long(&rf);
 }
 
@@ -1086,6 +1087,7 @@
 	rf.fp = fp;
 	rf.strings = PyList_New(0);
 	rf.depth = 0;
+	rf.ptr = rf.end = NULL;
 	result = r_object(&rf);
 	Py_DECREF(rf.strings);
 	return result;