diff --git a/lib/cpp/test/Makefile.am b/lib/cpp/test/Makefile.am
index 02c26ad..1829268 100644
--- a/lib/cpp/test/Makefile.am
+++ b/lib/cpp/test/Makefile.am
@@ -176,6 +176,7 @@
 	-I$(top_srcdir)/lib/cpp/src
 
 AM_CPPFLAGS = $(BOOST_CPPFLAGS)
+AM_CXXFLAGS = -Wall
 
 clean-local:
 	$(RM) -r gen-cpp