diff --git a/Makefile.am b/Makefile.am
index 1ee675a..44aba66 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -1,2 +1,4 @@
 
 SUBDIRS = src include examples docs tests
+
+CXXFLAGS = -Wall
diff --git a/src/Makefile.am b/src/Makefile.am
index ecf754a..f3c87bb 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -4,3 +4,5 @@ lib_LIBRARIES = libtclap.a
 libtclap_a_SOURCES = Arg.cpp CmdLine.cpp SwitchArg.cpp
 
 INCLUDES = -I$(top_srcdir)/include
+
+CXXFLAGS = -Wall