diff --git a/src/backend/storage/aio/read_stream.c b/src/backend/storage/aio/read_stream.c
index 4c3218846dd..f9152ca084b 100644
--- a/src/backend/storage/aio/read_stream.c
+++ b/src/backend/storage/aio/read_stream.c
@@ -470,7 +470,12 @@ read_stream_begin_relation(int flags,
 		LimitAdditionalLocalPins(&max_pinned_buffers);
 	else
 		LimitAdditionalPins(&max_pinned_buffers);
-	Assert(max_pinned_buffers > 0);
+
+	/*
+	 * The limit might be zero on a system configured with too few buffers for
+	 * the number of connections.  We need at least one to make progress.
+	 */
+	max_pinned_buffers = Max(1, max_pinned_buffers);
 
 	/*
 	 * We need one extra entry for buffers and per-buffer data, because users