diff --git a/bin/load_gen b/bin/load_gen
index a5b33cf11b66c6a0917c9578c29e2bfbefe1a633..9b019d0ee2af5984c9e3a53046dbc064c8f33365 100755
--- a/bin/load_gen
+++ b/bin/load_gen
@@ -234,6 +234,7 @@ function poll() {
         outstanding[act]--;
         if (undefined === completed[act]) completed[act] = [ 0, 0, 0 ];
         if (err) {
+          if (typeof err != 'string') err = err.toString();
           if (err.indexOf('server is too busy') != -1) {
             completed[act][2]++;
           } else {