diff --git a/gtsam/3rdparty/metis/libmetis/balance.c b/gtsam/3rdparty/metis/libmetis/balance.c
index 3fb0e6e56..f71df9c0e 100644
--- a/gtsam/3rdparty/metis/libmetis/balance.c
+++ b/gtsam/3rdparty/metis/libmetis/balance.c
@@ -20,7 +20,7 @@ void Balance2Way(ctrl_t *ctrl, graph_t *graph, real_t *ntpwgts)
 
   if (graph->ncon == 1) {
     /* return right away if the balance is OK */
-    if (iabs(ntpwgts[0]*graph->tvwgt[0]-graph->pwgts[0]) < 3*graph->tvwgt[0]/graph->nvtxs)
+    if (fabs(ntpwgts[0]*graph->tvwgt[0]-graph->pwgts[0]) < 3*graph->tvwgt[0]/graph->nvtxs)
       return;
 
     if (graph->nbnd > 0)