diff --git a/backend/src/langs.ts b/backend/src/langs.ts
index da59d07..7006be5 100644
--- a/backend/src/langs.ts
+++ b/backend/src/langs.ts
@@ -1061,6 +1061,8 @@ END
     repl: "tex",
     main: "main.tex",
     run: "tex main.tex",
+    lsp: "digestif",
+    lspLang: "tex",
     template: `\\message{Hello, world!}
 `,
   },
diff --git a/scripts/docker-install-phase3d.bash b/scripts/docker-install-phase3d.bash
index 6ff69b4..7766f19 100755
--- a/scripts/docker-install-phase3d.bash
+++ b/scripts/docker-install-phase3d.bash
@@ -38,6 +38,8 @@ tcl
 tcsh
 
 # TeX
+liblua5.3-dev
+luarocks
 texlive-binaries
 
 # Unlambda
diff --git a/scripts/docker-install-phase4.bash b/scripts/docker-install-phase4.bash
index 1821e21..5bc51cb 100755
--- a/scripts/docker-install-phase4.bash
+++ b/scripts/docker-install-phase4.bash
@@ -67,6 +67,9 @@ rustup component add rls rust-analysis rust-src
 # Shakespeare
 pip3 install shakespearelang
 
+# TeX
+luarocks install digestif
+
 # TypeScript
 npm install -g ts-node typescript