diff --git a/.local/bin/statusbar/nettraf b/.local/bin/statusbar/nettraf
index fa9eb30..ac43416 100755
--- a/.local/bin/statusbar/nettraf
+++ b/.local/bin/statusbar/nettraf
@@ -14,12 +14,12 @@ update() {
     sum=0
     for arg; do
         read -r i < "$arg"
-        sum=$(( $sum + $i ))
+        sum=$(( sum + i ))
     done
     cache=${XDG_CACHE_HOME:-$HOME/.cache}/${1##*/}
     [ -f "$cache" ] && read -r old < "$cache" || old=0
     printf %d\\n "$sum" > "$cache"
-    printf %d\\n $(( ($sum - $old) / 1024 ))
+    printf %d\\n $(( (sum - old) / 1024 ))
 }
 
 rx=$(update /sys/class/net/[ew]*/statistics/rx_bytes)