diff --git a/tests/Makefile.am b/tests/Makefile.am
index a7b1c09..ee8389c 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -5,7 +5,7 @@
 # TESTS                       =
 # endif
 TESTS                       = check_tree
-AM_CFLAGS = -ggdb $(DEPS_CFLAGS) -I$(top_builddir) -I$(top_builddir)/include  @CHECK_CFLAGS@
+AM_CFLAGS = -ggdb -Wall $(DEPS_CFLAGS) -I$(top_builddir) -I$(top_builddir)/include  @CHECK_CFLAGS@
 AM_LDFLAGS = $(DEPS_LIBS) -L$(top_builddir)/src -lr3 @CHECK_LIBS@