diff --git a/ghc.mk b/ghc.mk
index f864443e21fe6c075169d7074bf09c7dd8d1d845..eeb0d6a11dc18158178505f1cacc211ca820d28f 100644
--- a/ghc.mk
+++ b/ghc.mk
@@ -1350,7 +1350,7 @@ validate_build_xhtml:
 	cd libraries/xhtml && ./Setup configure --with-ghc="$(BINDIST_PREFIX)/bin/ghc" $(BINDIST_HADDOCK_FLAG) $(BINDIST_LIBRARY_FLAGS) --global --builddir=dist-bindist --prefix="$(BINDIST_PREFIX)"
 	cd libraries/xhtml && ./Setup build   --builddir=dist-bindist
 ifeq "$(HADDOCK_DOCS)" "YES"
-	cd libraries/xhtml && ./Setup haddock --builddir=dist-bindist
+	cd libraries/xhtml && ./Setup haddock --ghc-options=-optP-P --builddir=dist-bindist
 endif
 	cd libraries/xhtml && ./Setup install --builddir=dist-bindist
 	cd libraries/xhtml && ./Setup clean   --builddir=dist-bindist