diff --git a/examples/Makefile.am b/examples/Makefile.am
index f03f215..8e9ca63 100644
--- a/examples/Makefile.am
+++ b/examples/Makefile.am
@@ -9,6 +9,8 @@ EXTRA_PROGRAMS = happrox
 
 happrox_LDADD = $(LDADD) -lnetpbm
 
+happrox_CPPFLAGS = -I/usr/include/netpbm
+
 if HAS_NETPBM
 NETPBM_EXTRA = happrox
 endif
@@ -16,9 +18,7 @@ endif
 bin_PROGRAMS = \
 	transform \
 	delaunay \
-	$(NETPBM_EXTRA)
-
-noinst_PROGRAMS = \
+	$(NETPBM_EXTRA) \
 	set \
 	volume \
 	cleanup \