diff --git a/multicore/graph500par/sparseGraph.ml b/multicore/graph500par/sparseGraph.ml
index c37b773..47805f6 100644
--- a/multicore/graph500par/sparseGraph.ml
+++ b/multicore/graph500par/sparseGraph.ml
@@ -14,7 +14,10 @@ let rec add_edge (s,e,w) g =
   let old = Atomic.get g.(s) in
   let new_ = (e,w) :: old in
   if Atomic.compare_and_set g.(s) old new_ then ()
-  else add_edge (s,e,w) g
+  else begin
+    Domain.cpu_relax ();
+    add_edge (s,e,w) g
+  end
 
 let from s g =
   Atomic.get g.(s)