diff --git a/pmd-analyser.sh b/pmd-analyser.sh
index 40f2179..2ca30b9 100755
--- a/pmd-analyser.sh
+++ b/pmd-analyser.sh
@@ -1,7 +1,9 @@
-# shellcheck shell=sh
+#!/bin/bash
+
+# shellcheck shell=bash
 
 # Check whether to use latest version of PMD
-if [ "$PMD_VERSION" = 'latest' ]; then
+if [ "$PMD_VERSION" == 'latest' ]; then
     LATEST_TAG="$(curl -H "Accept: application/vnd.github.v3+json" https://api.github.com/repos/pmd/pmd/releases/latest | jq --raw-output '.tag_name')"
     PMD_VERSION="${LATEST_TAG#"pmd_releases/"}"
 fi
@@ -10,13 +12,13 @@ fi
 wget https://github.com/pmd/pmd/releases/download/pmd_releases%2F"${PMD_VERSION}"/pmd-bin-"${PMD_VERSION}".zip
 unzip pmd-bin-"${PMD_VERSION}".zip
 # Now either run the full analysis or files changed based on the settings defined
-if [ "$ANALYSE_ALL_CODE" = 'true' ]; then
+if [ "$ANALYSE_ALL_CODE" == 'true' ]; then
     pmd-bin-"${PMD_VERSION}"/bin/run.sh pmd -d "$FILE_PATH" -R "$RULES_PATH" -failOnViolation false -f sarif > pmd-raw-output.sarif
 else
-    if [ "$ACTION_EVENT_NAME" = 'pull_request' ]; then
+    if [ "$ACTION_EVENT_NAME" == 'pull_request' ]; then
         # Now to determine whether to get the files changed from a git diff or using the files changed in a GitHub Pull Request
         # Both options will generate a CSV file first with the files changed
-        if [ "$FILE_DIFF_TYPE" = 'git' ]; then
+        if [ "$FILE_DIFF_TYPE" == 'git' ]; then
             git diff --name-only --diff-filter=d origin/"$CURRENT_CODE"..origin/"${CHANGED_CODE#"refs/heads/"}" | paste -s -d "," >> diff-file.csv
         else
             curl -H "Accept: application/vnd.github.v3+json" -H "Authorization: token ${AUTH_TOKEN}" https://api.github.com/repos/"$REPO_NAME"/pulls/"$PR_NUMBER"/files | jq --raw-output '.[] .filename' | paste -s -d "," >> diff-file.csv
@@ -32,7 +34,7 @@ fi
 echo "::set-output name=error-found::false"
 while read -r rule; do
     RULE="$(echo "$rule" | jq --raw-output '.id')"
-    if [[ $RULE && "$ERROR_RULES" == *"$RULE"* ]]; then
+    if [[ "$RULE" && "$ERROR_RULES" == *"$RULE"* ]]; then
         echo "::set-output name=error-found::true"
         break
     fi