diff --git a/backend/src/langs.ts b/backend/src/langs.ts
index 385fcc6..92d2a9b 100644
--- a/backend/src/langs.ts
+++ b/backend/src/langs.ts
@@ -905,6 +905,9 @@ USE: io
       code: `let x = 123 * 234`,
       input: `x ;;`,
     },
+    lsp: {
+      start: "mono /opt/fsautocomplete/fsautocomplete.dll",
+    },
     template: `printfn "Hello, world!"
 `,
     timeout: 15,
diff --git a/scripts/docker-install-phase4.bash b/scripts/docker-install-phase4.bash
index bfed8f2..1366037 100755
--- a/scripts/docker-install-phase4.bash
+++ b/scripts/docker-install-phase4.bash
@@ -103,6 +103,11 @@ tar -xf euphor*.tar -C /opt/euphoria --strip-components=1
 ln -s /opt/euphoria/bin/exu /usr/bin/
 rm euphor*.tar
 
+# F#
+wget -nv https://github.com/fsharp/FsAutoComplete/releases/download/0.41.1/fsautocomplete.netcore.zip
+unzip -d /opt/fsautocomplete fsautocomplete.netcore.zip
+rm fsautocomplete.netcore.zip
+
 # Factor
 ver="$(curl -sSL https://factorcode.org/ | grep -Eo 'release\?os=linux[^>]+>[^<]+' | sed -E 's/[^>]+>//' | head -n1)"
 wget -nv "https://downloads.factorcode.org/releases/${ver}/factor-linux-x86-64-${ver}.tar.gz"