diff --git a/tools/callstats-from-telemetry.sh b/tools/callstats-from-telemetry.sh
index cea471cde8..3572b7e6ba 100755
--- a/tools/callstats-from-telemetry.sh
+++ b/tools/callstats-from-telemetry.sh
@@ -46,7 +46,7 @@ fi
 OUT=out.json
 if [[ -e $OUT ]]; then
   echo "# Creating backup for $OUT"
-  cp --backup=numbered $OUT $OUT.bak
+  cp $OUT $OUT.bak
 fi
 echo "# Writing to $OUT"
 
@@ -54,11 +54,14 @@ echo "# Writing to $OUT"
 function convert {
   NAME=$1
   JSON=$2
-  du -sh $JSON;
-  echo "Converting NAME=$NAME";
-  echo "," >> $OUT;
-  echo "\"$NAME\": " >> $OUT;
-  jq '[.traceEvents[].args | select(."runtime-call-stats" != null) | ."runtime-call-stats"]' $JSON >> $OUT;
+  # Check if any json file exists:
+  if ls $JSON 1> /dev/null 2>&1; then
+    du -sh $JSON;
+    echo "Converting NAME=$NAME";
+    echo "," >> $OUT;
+    echo "\"$NAME\": " >> $OUT;
+    jq '[.traceEvents[].args | select(."runtime-call-stats" != null) | ."runtime-call-stats"]' $JSON >> $OUT;
+  fi
 }
 
 
diff --git a/tools/callstats.html b/tools/callstats.html
index d00f48d8b5..2a797680bc 100644
--- a/tools/callstats.html
+++ b/tools/callstats.html
@@ -1543,23 +1543,27 @@ code is governed by a BSD-style license that can be found in the LICENSE file.
       // Instead of the default multi-page JSON:
       //    {"Version 1": { "Page 1": ..., ...}, "Version 2": {...}, ...}
       // In this case insert a single "Default" version as top-level entry.
-      let firstProperty = (object) => {
+      const  firstProperty = (object) => {
         for (let key in object) return object[key];
       };
-      let maybePage = firstProperty(json);
-      let maybeMetrics = firstProperty(maybePage);
-      let tempName = name ? name : new Date().toISOString();
-      tempName = window.prompt('Enter a name for the loaded file:', tempName);
-      if ('count' in maybeMetrics && 'duration' in maybeMetrics) {
+      const maybeMetrics = firstProperty(json);
+      const maybeMetric = firstProperty(maybeMetrics);
+      const tempName = name ? name : new Date().toISOString();
+      const getFileName =
+          () => window.prompt('Enter a name for the loaded file:', tempName);
+      if ('count' in maybeMetric && 'duration' in maybeMetric) {
         return {
-          [tempName]: json
+          [getFileName()]: json
         }
       }
       // Legacy fallback where the metrics are encoded as arrays:
       //  { PAGE: [[metric_name, ...], [...], ]}
-      if (Array.isArray(maybeMetrics)) {
+      // Also, make sure we don't have the versioned array-style:
+      // { VERSION: { PAGE: [[metric_name, ...], [...], ]}, ...}
+      const innerArray = firstProperty(maybeMetrics);
+      if (Array.isArray(maybeMetric) && !Array.isArray(innerArray)) {
         return {
-          [tempName]: json
+          [getFileName()]: json
         }
       }
       return json
@@ -2705,4 +2709,4 @@ code is governed by a BSD-style license that can be found in the LICENSE file.
   </div>
 </body>
 
-</html>
\ No newline at end of file
+</html>
diff --git a/tools/callstats.py b/tools/callstats.py
index a5e6bfe69c..1b76d0c166 100755
--- a/tools/callstats.py
+++ b/tools/callstats.py
@@ -494,11 +494,9 @@ def print_stats(S, args):
 
 
 def extract_domain(filename):
-  print(filename)
   # Extract domain name: domain#123.txt or domain_123.txt
   match = re.match(r'^(.*?)[^a-zA-Z]?[0-9]+?.txt', filename)
   domain = match.group(1)
-  print(domain)
   return domain