diff --git a/lemon/Makefile.am b/lemon/Makefile.am
--- a/lemon/Makefile.am
+++ b/lemon/Makefile.am
@@ -36,6 +36,7 @@
 	lemon/maps.h \
 	lemon/math.h \
 	lemon/path.h \
+	lemon/radix_sort.h \
         lemon/random.h \
 	lemon/smart_graph.h \
         lemon/time_measure.h \