diff --git a/.lgtm.yml b/.lgtm.yml
index 1c7be044cb..eb17bd52de 100644
--- a/.lgtm.yml
+++ b/.lgtm.yml
@@ -1,17 +1,24 @@
+---
+# vi: ts=2 sw=2 et:
+
 extraction:
   cpp:
     prepare:
       packages:
-        - python3-pip
-        - python3-setuptools
-        - python3-wheel
         - libpwquality-dev
         - libfdisk-dev
         - libp11-kit-dev
         - libssl-dev
-    after_prepare:
-      - pip3 install meson
-      - export PATH="$HOME/.local/bin/:$PATH"
+    before_index:
+      # /tmp has `noexec` set in the LGTM infra which breaks meson's
+      # compilation checks. Let's temporarily override TMPDIR to /var/tmp which
+      # should work as expected
+      # See: https://discuss.lgtm.com/t/meson-fails-to-determine-sizes-of-basic-data-types/2639
+      - export TMPDIR=/var/tmp
+    index:
+      build_command:
+        - meson build
+        - ninja -C build
   python:
     python_setup:
       version: 3