diff --git a/devtools/benchmarks-tools/cronjob.sh b/devtools/benchmarks-tools/cronjob.sh
index ae36ca81e39626df65bde78680b20ebfa1aad19d..7e9b1dcf8d22982def86a6db3040c0892c8c0764 100755
--- a/devtools/benchmarks-tools/cronjob.sh
+++ b/devtools/benchmarks-tools/cronjob.sh
@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/usr/bin/env bash
 
 #############################################################################
 #                                                                           #
@@ -40,10 +40,10 @@ TODAY=$(date +"%Y%m%d_%H%M")
 # messages using the gas-benchmarks-reports Slack application.
 # The file can only be read by mclaren, its owner. This is to prevent anybody to
 # use the application to send messages.
-# C04HZHR11DW is the identifier for the #gas-benchmarks-reports channel (it can
+# C088AUBEB6Y is the identifier for the #core-layer1-gas-benchmarks-reports channel (it can
 # be found in its URL).
 slack() {
-  curl -X POST -H 'Authorization: Bearer '"$(cat /data/tezos-benchmarks/slack_token)" -H 'Content-type: application/json; charset=utf-8' --data "{\"channel\":\"C04HZHR11DW\",\"text\":\"$1\"}" https://tezos-dev.slack.com/api/chat.postMessage
+  curl -X POST -H 'Authorization: Bearer '"$(cat /data/tezos-benchmarks/slack_token)" -H 'Content-type: application/json; charset=utf-8' --data "{\"channel\":\"C088AUBEB6Y\",\"text\":\"$1\"}" https://tezos.slack.com/api/chat.postMessage
 }
 
 anomaly() {
diff --git a/devtools/benchmarks-tools/run_all_benchmarks_on_latest_master.sh b/devtools/benchmarks-tools/run_all_benchmarks_on_latest_master.sh
index 3d15d9da0fa10cb885bc2e503e089e5340fef45c..82d954234c8d5322f7a436394dc5535a2925031e 100755
--- a/devtools/benchmarks-tools/run_all_benchmarks_on_latest_master.sh
+++ b/devtools/benchmarks-tools/run_all_benchmarks_on_latest_master.sh
@@ -89,6 +89,9 @@ cd tezos
 dated_log "Compiling dependencies"
 # shellcheck disable=SC1091
 . "/home/mclaren/.cargo/env"
+# Reset switch
+rm -rf ../.opam
+opam init --bare --root /data/tezos-benchmarks/.opam --confirm-level=no
 # OPAMSOLVERTIMEOUT=0 means that the opam solver won't timeout
 make OPAMSOLVERTIMEOUT=0 build-dev-deps
 eval "$(opam env)"
diff --git a/devtools/benchmarks-tools/watch_regressions.sh b/devtools/benchmarks-tools/watch_regressions.sh
index cf73424a184e94cbeee69eb7b3e8883d479b8ea4..bb75efd59d1e648cf67a562e4d4d52aa394867a4 100755
--- a/devtools/benchmarks-tools/watch_regressions.sh
+++ b/devtools/benchmarks-tools/watch_regressions.sh
@@ -76,7 +76,18 @@ slack() {
 
 slack_send_file() {
   if [ "$DISABLE_SLACK_MESSAGING" = "" ]; then
-    curl -F file=@"$1" -F "initial_comment=$2" -F channels="$CHAN" -F token="$TOK" https://tezos.slack.com/api/files.upload
+    FILESIZE="$(stat --printf="%s" "$1")"
+    RESPONSE="$(curl -F filename="$1" -F length="$FILESIZE" -F token="$TOK" https://tezos.slack.com/api/files.getUploadURLExternal)"
+    OK="$(echo "$RESPONSE" | jq -r .ok)"
+    if [ "$OK" = "true" ]; then
+      URL="$(echo "$RESPONSE" | jq -r .upload_url)"
+      ID="$(echo "$RESPONSE" | jq -r .file_id)"
+      curl -X POST -F filename=@"$1" "$URL"
+      curl -X POST -F files="[{\"id\":\"$ID\", \"title\":\"$1\"}]" -F "initial_comment=$2" -F channels="$CHAN" -F token="$TOK" https://tezos.slack.com/api/files.completeUploadExternal
+    else
+      ERROR="$(echo "$RESPONSE" | jq -r .error)"
+      echo "Error: could not send \"$1\" on Slack with message \"$2\". Error: \"$ERROR\""
+    fi
   else
     echo "File \"$1\" would be sent on Slack with message \"$2\" but Slack messaging has been disabled."
   fi