diff --git a/util/analyze-contention-log.sh b/util/analyze-contention-log.sh
index 6ad58e489b..b8cd6d0f77 100755
--- a/util/analyze-contention-log.sh
+++ b/util/analyze-contention-log.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/bin/bash -eu
 # Copyright 2025 The OpenSSL Project Authors. All Rights Reserved.
 #
 # Licensed under the Apache License 2.0 (the "License").
@@ -37,7 +37,7 @@ awk '
     BEGIN {RS = ""; FS = "\n"}
     {file_num++; print > ("stacktrace" file_num ".txt")}' ./$LOGFILEBASE
 popd > /dev/null
-rm $TEMPDIR/individual_files/$LOGFILEBASE
+rm -f $TEMPDIR/individual_files/$LOGFILEBASE
 
 #
 # Make some associative arrays to track our stats
@@ -48,7 +48,7 @@ declare -A latency_counts
 
 echo "Gathering latencies"
 FILECOUNT=$(ls $TEMPDIR/individual_files/stacktrace*.* | wc -l)
-let currentidx=0
+currentidx=0
 
 #
 # Look at every stack trace, get and record its latency, and hash value
@@ -61,8 +61,8 @@ do
     #now compute its sha1sum
     SHA1SUM=$(sha1sum $i | awk '{print $1}')
     filenames["$SHA1SUM"]=$i
-    let CUR_LATENCY=0
-    let LATENCY_COUNT=0
+    CUR_LATENCY=0
+    LATENCY_COUNT=0
 
     #
     # If we already have a latency total for this hash value
@@ -71,8 +71,8 @@ do
     #
     if [[ -v total_latency["$SHA1SUM"] ]]
     then
-        let CUR_LATENCY=${total_latency["$SHA1SUM"]}
-        let LATENCY_COUNT=${latency_counts["$SHA1SUM"]}
+        CUR_LATENCY=${total_latency["$SHA1SUM"]}
+        LATENCY_COUNT=${latency_counts["$SHA1SUM"]}
     fi
 
     #
@@ -82,7 +82,7 @@ do
     total_latency["$SHA1SUM"]=$(dc -e "$CUR_LATENCY $LATENCY + p")
     latency_counts["$SHA1SUM"]=$(dc -e "$LATENCY_COUNT 1 + p")
     echo -e -n "FILE $currentidx/$FILECOUNT \r"
-    let currentidx=$currentidx+1
+    currentidx=$((currentidx + 1))
 done
 
 #