diff --git a/drivers/infiniband/sw/siw/siw.h b/drivers/infiniband/sw/siw/siw.h
index 1c78c1ca7d7a..cec5cccd2e75 100644
--- a/drivers/infiniband/sw/siw/siw.h
+++ b/drivers/infiniband/sw/siw/siw.h
@@ -137,7 +137,7 @@ struct siw_pble {
 struct siw_pbl {
 	unsigned int num_buf;
 	unsigned int max_buf;
-	struct siw_pble pbe[];
+	struct siw_pble pbe[] __counted_by(max_buf);
 };
 
 /*