diff --git a/.github/workflows/clean.yml b/.github/workflows/clean.yml
index 547aaa4..bfc865d 100644
--- a/.github/workflows/clean.yml
+++ b/.github/workflows/clean.yml
@@ -17,6 +17,7 @@ jobs:
       GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
     steps:
       - name: Delete artifacts
+        shell: bash {0}
         run: |
           # Customize those three lines with your repository and credentials:
           REPO=${GITHUB_API_URL}/repos/${{ github.repository }}
@@ -25,7 +26,7 @@ jobs:
           ghapi() { curl --silent --location --user _:$GITHUB_TOKEN "$@"; }
 
           # A temporary file which receives HTTP response headers.
-          TMPFILE=/tmp/tmp.$$
+          TMPFILE=$(mktemp)
 
           # An associative array, key: artifact name, value: number of artifacts of that name.
           declare -A ARTCOUNT
diff --git a/project/plugins.sbt b/project/plugins.sbt
index 7d1c91d..e4c275a 100644
--- a/project/plugins.sbt
+++ b/project/plugins.sbt
@@ -1,5 +1,5 @@
 addSbtPlugin("com.typesafe" % "sbt-mima-plugin" % "1.1.3")
 addSbtPlugin("com.typesafe.sbt" % "sbt-git" % "1.0.2")
 addSbtPlugin("org.scalameta" % "sbt-scalafmt" % "2.5.2")
-addSbtPlugin("com.github.sbt" % "sbt-github-actions" % "0.17.0")
+addSbtPlugin("com.github.sbt" % "sbt-github-actions" % "0.18.0")
 addSbtPlugin("com.github.sbt" % "sbt-ci-release" % "1.5.10")