diff --git a/src/Makefile.am b/src/Makefile.am
index 2cd56b5cdae128701557241ddfe393acfa1d4301..5e8f89a71a38ee10545b14f011129bc691f6d5ca 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -15,6 +15,8 @@ check-am:
 	./bisection-simpler-example2
 	./bisection-simpler-example2-gradient
 
+AM_CXXFLAGS = -Wall -Wextra
+
 AM_CPPFLAGS = \
 	$(DUNE_CPPFLAGS) \
 	$(ALUGRID_CPPFLAGS)