diff --git a/src/liblzma/common/outqueue.c b/src/liblzma/common/outqueue.c
index b9eac16d..d7a87d9a 100644
--- a/src/liblzma/common/outqueue.c
+++ b/src/liblzma/common/outqueue.c
@@ -101,7 +101,11 @@ extern void
 lzma_outq_end(lzma_outq *outq, lzma_allocator *allocator)
 {
 	lzma_free(outq->bufs, allocator);
+	outq->bufs = NULL;
+
 	lzma_free(outq->bufs_mem, allocator);
+	outq->bufs_mem = NULL;
+
 	return;
 }