diff --git a/src/vs/base/node/cpuUsage.sh b/src/vs/base/node/cpuUsage.sh
index 3d42b36dc20..8e07feffaf7 100755
--- a/src/vs/base/node/cpuUsage.sh
+++ b/src/vs/base/node/cpuUsage.sh
@@ -30,7 +30,7 @@ for PID in "$@"; do
   fi
 
   PROCESS_BEFORE_TIMES[$ITER]=$PROCESS_TIME_BEFORE
-  ((ITER++))
+  ((++ITER))
 done
 
 # Wait for a second
@@ -60,5 +60,5 @@ for PID in "$@"; do
 
   # Parent script reads from stdout, so echo result to be read
   echo $CPU_USAGE
-  ((ITER++))
+  ((++ITER))
 done