diff --git a/md-to-html.cabal b/md-to-html.cabal
index cbcab70..6b63c48 100644
--- a/md-to-html.cabal
+++ b/md-to-html.cabal
@@ -60,7 +60,9 @@ library
    build-depends:    base ^>=4.19.1.0,
                       HUnit,
                       megaparsec,
-                      text
+                      parser-combinators,
+                      text,
+                      MissingH
 
 executable md-to-html-runner
     -- Import common warning flags.