diff --git a/lemon/Makefile.am b/lemon/Makefile.am
--- a/lemon/Makefile.am
+++ b/lemon/Makefile.am
@@ -36,6 +36,7 @@
         lemon/grid_graph.h \
 	lemon/hypercube_graph.h \
 	lemon/kruskal.h \
+	lemon/hao_orlin.h \
 	lemon/lgf_reader.h \
 	lemon/lgf_writer.h \
 	lemon/list_graph.h \