diff --git a/src/bin/pg_basebackup/bbstreamer_lz4.c b/src/bin/pg_basebackup/bbstreamer_lz4.c
index 67f841d96a9..8e8352a450c 100644
--- a/src/bin/pg_basebackup/bbstreamer_lz4.c
+++ b/src/bin/pg_basebackup/bbstreamer_lz4.c
@@ -170,7 +170,11 @@ bbstreamer_lz4_compressor_content(bbstreamer *streamer,
 	 * forward the content to next streamer and empty the buffer.
 	 */
 	out_bound = LZ4F_compressBound(len, &mystreamer->prefs);
-	Assert(mystreamer->base.bbs_buffer.maxlen >= out_bound);
+
+	/* Enlarge buffer if it falls short of compression bound. */
+	if (mystreamer->base.bbs_buffer.maxlen < out_bound)
+		enlargeStringInfo(&mystreamer->base.bbs_buffer, out_bound);
+
 	if (avail_out < out_bound)
 	{
 			bbstreamer_content(mystreamer->base.bbs_next, member,