diff --git a/DocGen4/Load.lean b/DocGen4/Load.lean
index 929d492..113bade 100644
--- a/DocGen4/Load.lean
+++ b/DocGen4/Load.lean
@@ -10,7 +10,9 @@ namespace DocGen4
 open Lean System IO
 
 def envOfImports (imports : Array Name) : IO Environment := do
- importModules (imports.map (Import.mk · false)) Options.empty (leakEnv := true)
+  -- needed for modules which use syntax registered with `initialize add_parser_alias ..`
+  unsafe Lean.enableInitializersExecution
+  importModules (imports.map (Import.mk · false)) Options.empty (leakEnv := true)
 
 def loadInit (imports : Array Name) : IO Hierarchy := do
  let env ← envOfImports imports