diff --git a/src/drivers/infiniband/hermon.c b/src/drivers/infiniband/hermon.c
index 79d60609..2199a9d9 100644
--- a/src/drivers/infiniband/hermon.c
+++ b/src/drivers/infiniband/hermon.c
@@ -2135,7 +2135,7 @@ static int hermon_map_vpm ( struct hermon *hermon,
 		if ( ( low - size ) >= start ) {
 			low -= size;
 			pa = low;
-		} else if ( ( high + size ) <= end ) {
+		} else if ( high <= ( end - size ) ) {
 			pa = high;
 			high += size;
 		} else {