diff --git a/stream/stream.c b/stream/stream.c
index dd67825dd5..43a7f51a60 100644
--- a/stream/stream.c
+++ b/stream/stream.c
@@ -803,7 +803,7 @@ int stream_skip_bom(struct stream *s)
 struct bstr stream_read_complete(struct stream *s, void *talloc_ctx,
                                  int max_size)
 {
-    if (max_size > 1000000000)
+    if (max_size <= 0 || max_size > STREAM_MAX_READ_SIZE)
         abort();
 
     int bufsize;
diff --git a/stream/stream.h b/stream/stream.h
index 423ba12d91..58b55e1a43 100644
--- a/stream/stream.h
+++ b/stream/stream.h
@@ -32,6 +32,9 @@
 // it's guaranteed that you can seek back by <= of this size again.
 #define STREAM_BUFFER_SIZE 2048
 
+// Maximum size of a complete read.
+#define STREAM_MAX_READ_SIZE (INT_MAX - 1)
+
 // flags for stream_open_ext (this includes STREAM_READ and STREAM_WRITE)
 
 // stream->mode