[build] Add missing explicit references in docs

diff --git a/docs/docs.make b/docs/docs.make
index 4f2d964e5b93f89ff144f23bd9c4180869f9bf89..c19ba5c33758cc2e935f459b907e8b3d22736a4a 100644 (file)
--- a/docs/docs.make
+++ b/docs/docs.make
@@ -13,10 +13,10 @@ ASSEMBLED_DOCS = \
        monoapi.tree monoapi.zip
 
 convert.exe: $(srcdir)/convert.cs AgilityPack.dll
-       $(CSCOMPILE) -out:$@ $< -r:AgilityPack.dll
+       $(CSCOMPILE) -r:System.Xml.dll -out:$@ $< -r:AgilityPack.dll
 
 AgilityPack.dll:
-       $(CSCOMPILE) -target:library -out:$@ $(srcdir)/HtmlAgilityPack/*.cs
+       $(CSCOMPILE) -r:System.dll -r:System.Xml.dll -target:library -out:$@ $(srcdir)/HtmlAgilityPack/*.cs
 
 monoapi.zip: monoapi.tree
        @test -f $@ || { rm -f $< && $(MAKE) $<; }