diff --git a/tools/Makefile.am b/tools/Makefile.am
index f8879b0..c85ffeb 100644
--- a/tools/Makefile.am
+++ b/tools/Makefile.am
@@ -16,3 +16,5 @@
 	pci.cpp \
 	p2a.cpp \
 	$(top_srcdir)/internal/sys.cpp
+
+SUBDIRS = . test