diff --git a/action.yml b/action.yml
index a6ca929..8e916b5 100644
--- a/action.yml
+++ b/action.yml
@@ -13,6 +13,10 @@ runs:
         REVIEWDOG_VERSION: ${{ inputs.reviewdog_version }}
         REVIEWDOG_TEMPDIR: ${{ runner.temp }}
     - run: |
+        if ! command -v reviewdog >/dev/null 2>&1; then
+          echo "reviewdog was not installed"
+          exit 1
+        fi
         echo "::group::📖 reviewdog -h"
         reviewdog -h 2>&1 || true
         echo "::endgroup::"
diff --git a/install.sh b/install.sh
index 3d964dc..424e909 100755
--- a/install.sh
+++ b/install.sh
@@ -1,5 +1,7 @@
 #!/bin/bash
 
+set -euo pipefail
+
 VERSION="${REVIEWDOG_VERSION:-latest}"
 
 TEMP="${REVIEWDOG_TEMPDIR}"