diff --git a/.github/codeql-config.yml b/.github/codeql-config.yml
new file mode 100644
index 0000000000..447e53bd1b
--- /dev/null
+++ b/.github/codeql-config.yml
@@ -0,0 +1,12 @@
+---
+# vi: ts=2 sw=2 et:
+# SPDX-License-Identifier: LGPL-2.1-or-later
+name: "CodeQL config"
+
+disable-default-queries: false
+
+queries:
+  - name: Enable possibly useful queries which are disabled by default
+    uses: ./.github/codeql-custom.qls
+  - name: systemd-specific CodeQL queries
+    uses: ./.lgtm/cpp-queries/
diff --git a/.github/codeql-custom.qls b/.github/codeql-custom.qls
new file mode 100644
index 0000000000..c5b842cc1c
--- /dev/null
+++ b/.github/codeql-custom.qls
@@ -0,0 +1,33 @@
+---
+# vi: ts=2 sw=2 et syntax=yaml:
+# SPDX-License-Identifier: LGPL-2.1-or-later
+#
+# Note: it is not recommended to directly reference the respective queries from
+#       the github/codeql repository, so we have to "dance" around it using
+#       a custom QL suite
+# See:
+#   - https://docs.github.com/en/code-security/code-scanning/automatically-scanning-your-code-for-vulnerabilities-and-errors/configuring-code-scanning#running-additional-queries
+#   - https://github.com/github/codeql-action/issues/430#issuecomment-806092120
+#   - https://codeql.github.com/docs/codeql-cli/creating-codeql-query-suites/
+
+- import: codeql-suites/cpp-lgtm.qls
+  from: codeql/cpp-queries
+- include:
+    id:
+      - cpp/bad-strncpy-size
+      - cpp/declaration-hides-variable
+      - cpp/inconsistent-null-check
+      - cpp/mistyped-function-arguments
+      - cpp/nested-loops-with-same-variable
+      - cpp/sizeof-side-effect
+      - cpp/suspicious-pointer-scaling
+      - cpp/suspicious-pointer-scaling-void
+      - cpp/suspicious-sizeof
+      - cpp/unsafe-strcat
+      - cpp/unsafe-strncat
+      - cpp/unsigned-difference-expression-compared-zero
+      - cpp/unused-local-variable
+    tags:
+      - "security"
+      - "correctness"
+    severity: "error"
diff --git a/.github/workflows/codeql-analysis.yml b/.github/workflows/codeql-analysis.yml
index db264e6490..492061353f 100644
--- a/.github/workflows/codeql-analysis.yml
+++ b/.github/workflows/codeql-analysis.yml
@@ -7,6 +7,10 @@ name: "CodeQL"
 on:
   pull_request:
     branches: [main]
+    paths:
+      - .github/codeql-config.yml
+      - .github/codeql-custom.qls
+      - .github/workflows/codeql-analysis.yml
   # It takes the workflow approximately 30 minutes to analyze the code base
   # so it doesn't seem to make much sense to trigger it on every PR or commit.
   # It runs daily at 01:00 to avoid colliding with the Coverity workflow.
@@ -20,7 +24,6 @@ jobs:
   analyze:
     name: Analyze
     runs-on: ubuntu-latest
-    if: github.event_name == 'schedule' || github.event.pull_request.user.login == 'dependabot[bot]'
     concurrency:
       group: ${{ github.workflow }}-${{ matrix.language }}-${{ github.ref }}
       cancel-in-progress: true
@@ -41,6 +44,7 @@ jobs:
       uses: github/codeql-action/init@546b30f35ae5a3db0e0be1843008c2224f71c3b0
       with:
         languages: ${{ matrix.language }}
+        config-file: ./.github/codeql-config.yml
 
     - run: sudo -E .github/workflows/unit_tests.sh SETUP
 
diff --git a/.lgtm.yml b/.lgtm.yml
index e27fa169c5..86fd0e742c 100644
--- a/.lgtm.yml
+++ b/.lgtm.yml
@@ -1,5 +1,6 @@
 ---
 # vi: ts=2 sw=2 et:
+# SPDX-License-Identifier: LGPL-2.1-or-later
 
 # Explicitly enable certain checks which are hidden by default
 queries:
diff --git a/.lgtm/cpp-queries/qlpack.yml b/.lgtm/cpp-queries/qlpack.yml
new file mode 100644
index 0000000000..a1a2dec6d6
--- /dev/null
+++ b/.lgtm/cpp-queries/qlpack.yml
@@ -0,0 +1,11 @@
+---
+# vi: ts=2 sw=2 et syntax=yaml:
+# SPDX-License-Identifier: LGPL-2.1-or-later
+
+library: false
+name: systemd/cpp-queries
+version: 0.0.1
+dependencies:
+  codeql/cpp-all: "*"
+  codeql/suite-helpers: "*"
+extractor: cpp