diff --git a/lemon/Makefile.am b/lemon/Makefile.am
--- a/lemon/Makefile.am
+++ b/lemon/Makefile.am
@@ -110,6 +110,7 @@
 	lemon/network_simplex.h \
 	lemon/pairing_heap.h \
 	lemon/path.h \
+	lemon/planarity.h \
 	lemon/preflow.h \
 	lemon/radix_heap.h \
 	lemon/radix_sort.h \