diff --git a/lemon/Makefile.am b/lemon/Makefile.am
--- a/lemon/Makefile.am
+++ b/lemon/Makefile.am
@@ -13,11 +13,14 @@
 lemon_libemon_la_LDFLAGS = $(GLPK_LIBS) $(CPLEX_LIBS) $(SOPLEX_LIBS)
 
 lemon_HEADERS += \
+        lemon/concept_check.h \
 	lemon/list_graph.h \
+        lemon/maps.h \
         lemon/tolerance.h
 
 bits_HEADERS += \
         lemon/bits/invalid.h \
         lemon/bits/utility.h
 
-concept_HEADERS +=
+concept_HEADERS += \
+        lemon/concepts/maps.h