diff --git a/fisher.fish b/fisher.fish
index b9e9624..6f5d43b 100644
--- a/fisher.fish
+++ b/fisher.fish
@@ -473,6 +473,6 @@ function _fisher_now -a elapsed
         case Darwin \*BSD
             command perl -MTime::HiRes -e 'printf("%.0f\n", (Time::HiRes::time() * 1000) - $ARGV[0])' $elapsed
         case \*
-            command date "+%s%3N" | command awk -v ELAPSED="$elapsed" '{ print $0 - ELAPSED }'
+            math (command date "+%s%3N") - "0$elapsed"
     end
 end