diff --git a/pkgs/servers/matrix-synapse/matrix-appservice-irc/default.nix b/pkgs/servers/matrix-synapse/matrix-appservice-irc/default.nix
index d76846bd2c4a..f8b0711f10bc 100644
--- a/pkgs/servers/matrix-synapse/matrix-appservice-irc/default.nix
+++ b/pkgs/servers/matrix-synapse/matrix-appservice-irc/default.nix
@@ -24,6 +24,9 @@ ourNodePackages.package.override {
   dontAutoPatchelf = true;
 
   postInstall = ''
+    # Compile typescript
+    npm run build
+
     makeWrapper '${nodejs}/bin/node' "$out/bin/matrix-appservice-irc" \
       --add-flags "$out/lib/node_modules/matrix-appservice-irc/app.js"
   '';