diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 0000000..93b25c2
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,97 @@
+name: CI
+
+# The tests live in the plugin repository (https://github.com/codeling/bfstop,
+# see tests/README.md there); they cover plugin and component together.
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+jobs:
+  syntax:
+    name: Syntax check (PHP ${{ matrix.php }})
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        php: ['8.1', '8.4']
+    steps:
+      - uses: actions/checkout@v7
+      - uses: shivammathur/setup-php@v2
+        with:
+          php-version: ${{ matrix.php }}
+          coverage: none
+      - name: Check PHP syntax
+        run: find . -name '*.php' -not -path './.git/*' -print0 | xargs -0 -n1 php -l
+
+  integration:
+    name: Joomla ${{ matrix.joomla }}, ${{ matrix.db }}, PHP ${{ matrix.php }}
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - { joomla: 5.4.8, php: '8.2', db: 'mysql:8.0' }
+          - { joomla: 5.4.8, php: '8.2', db: 'postgres:12' }
+          - { joomla: 6.1.3, php: '8.4', db: 'mariadb:11.4' }
+          - { joomla: 6.1.3, php: '8.4', db: 'postgres:17' }
+    env:
+      JOOMLA_VERSION: ${{ matrix.joomla }}
+      DB_HOST: 127.0.0.1
+      DB_NAME: joomla
+      DB_PASS: bfstop-test
+    steps:
+      - name: Set paths
+        run: |
+          {
+            echo "JOOMLA_ROOT=$RUNNER_TEMP/joomla"
+            echo "COM_BFSTOP_ROOT=$GITHUB_WORKSPACE"
+            echo "PLUGIN_ROOT=$RUNNER_TEMP/bfstop"
+          } >> "$GITHUB_ENV"
+      - uses: actions/checkout@v7
+
+      # use the plugin's branch of the same name if there is one (for changes
+      # spanning both), else main
+      - name: Determine bfstop branch
+        id: plugin
+        run: |
+          branch="${GITHUB_HEAD_REF:-$GITHUB_REF_NAME}"
+          if git ls-remote --exit-code --heads https://github.com/codeling/bfstop.git "$branch" > /dev/null; then
+            echo "ref=$branch" >> "$GITHUB_OUTPUT"
+          else
+            echo "ref=main" >> "$GITHUB_OUTPUT"
+          fi
+      - uses: actions/checkout@v7
+        with:
+          repository: codeling/bfstop
+          ref: ${{ steps.plugin.outputs.ref }}
+          path: bfstop
+      - name: Move bfstop checkout out of the component's
+        run: mv bfstop "$PLUGIN_ROOT"
+
+      - uses: shivammathur/setup-php@v2
+        with:
+          php-version: ${{ matrix.php }}
+          extensions: mysqli, pdo_mysql, pgsql, pdo_pgsql, zip, mbstring, intl, gd
+          tools: phpunit:11
+          coverage: none
+
+      - name: Start database (${{ matrix.db }})
+        env:
+          DB_IMAGE: ${{ matrix.db }}
+        run: '"$PLUGIN_ROOT"/tests/ci/start-database.sh'
+
+      - name: Install Joomla, bfstop and com_bfstop
+        run: '"$PLUGIN_ROOT"/tests/ci/install-joomla.sh'
+
+      - name: Tests
+        run: phpunit -c "$PLUGIN_ROOT"/tests/phpunit.xml.dist
+
+      - name: Plugin log
+        if: failure()
+        run: cat "$JOOMLA_ROOT"/administrator/logs/*.php || true
diff --git a/admin/src/Controller/DisplayController.php b/admin/src/Controller/DisplayController.php
index 67eebe6..fe31faa 100644
--- a/admin/src/Controller/DisplayController.php
+++ b/admin/src/Controller/DisplayController.php
@@ -43,7 +43,9 @@ function warnIfAdminUserExists()
 		try
 		{
 			$db = Factory::getDbo();
-			$query = "SELECT COUNT(*) FROM #__users u WHERE u.username='admin'";
+			// LOWER: also catch "Admin" etc. on PostgreSQL, which (unlike
+			// MySQL's default collations) compares case-sensitively
+			$query = "SELECT COUNT(*) FROM #__users u WHERE LOWER(u.username)='admin'";
 			$db->setQuery($query);
 			if ($db->loadResult() > 0)
 			{
diff --git a/admin/src/Table/AllowTable.php b/admin/src/Table/AllowTable.php
index aca5d7d..00af5bf 100644
--- a/admin/src/Table/AllowTable.php
+++ b/admin/src/Table/AllowTable.php
@@ -19,4 +19,17 @@ function __construct(DatabaseDriver $db)
 	{
 		parent::__construct('#__bfstop_allowlist', 'id', $db);
 	}
+
+	public function check()
+	{
+		// a new entry comes with an empty id from the edit form; MySQL turns
+		// that into the next auto-increment value, but PostgreSQL rejects it
+		// (as NULL for the id column) - 0 makes Joomla leave the id out of
+		// the INSERT on both (issue bfstop#206)
+		if (empty($this->id))
+		{
+			$this->id = 0;
+		}
+		return parent::check();
+	}
 }
diff --git a/admin/src/Table/BlockTable.php b/admin/src/Table/BlockTable.php
index f8a6da8..0f6668f 100644
--- a/admin/src/Table/BlockTable.php
+++ b/admin/src/Table/BlockTable.php
@@ -19,4 +19,17 @@ function __construct(DatabaseDriver $db)
 	{
 		parent::__construct('#__bfstop_bannedip', 'id', $db);
 	}
+
+	public function check()
+	{
+		// a new entry comes with an empty id from the edit form; MySQL turns
+		// that into the next auto-increment value, but PostgreSQL rejects it
+		// (as NULL for the id column) - 0 makes Joomla leave the id out of
+		// the INSERT on both (issue bfstop#206)
+		if (empty($this->id))
+		{
+			$this->id = 0;
+		}
+		return parent::check();
+	}
 }
diff --git a/site/src/Model/TokenunblockModel.php b/site/src/Model/TokenunblockModel.php
index b4c921b..91d0792 100644
--- a/site/src/Model/TokenunblockModel.php
+++ b/site/src/Model/TokenunblockModel.php
@@ -23,9 +23,10 @@ public function unblock($token, $logger)
 		// prune old tokens:
 		try
 		{
+			// cutoff computed in PHP, as DATE_ADD is MySQL-only (issue bfstop#206)
 			$this->_db->setQuery('DELETE FROM #__bfstop_unblock_token '.
-				'WHERE DATE_ADD(crdate, INTERVAL '.self::TokenValidDays.' DAY) < '.
-				$this->_db->quote(date('Y-m-d H:i:s')));
+				'WHERE crdate < '.
+				$this->_db->quote(date('Y-m-d H:i:s', time() - self::TokenValidDays * 86400)));
 			$this->_db->execute();
 			// get token:
 			$this->_db->setQuery('SELECT * FROM #__bfstop_unblock_token WHERE token='.