diff --git a/pkgs/by-name/st/strictdoc/package.nix b/pkgs/by-name/st/strictdoc/package.nix
index 668addd1ab4d..e543f6ed5017 100644
--- a/pkgs/by-name/st/strictdoc/package.nix
+++ b/pkgs/by-name/st/strictdoc/package.nix
@@ -60,6 +60,7 @@ python3.pkgs.buildPythonApplication rec {
     "python-datauri"
     "xlsxwriter"
     "lxml"
+    "textx"
   ];
 
   pythonImportsCheck = [ "strictdoc" ];