diff --git a/configure.ac b/configure.ac
index f3977e7..9dc4233 100644
--- a/configure.ac
+++ b/configure.ac
@@ -6,7 +6,6 @@ AM_SILENT_RULES([yes])
 AC_PROG_CC
 AC_LANG([C])
 AC_PROG_INSTALL
-AM_CFLAGS="-Wall"
 
 PKG_PROG_PKG_CONFIG
 AC_ARG_WITH([bash-completion-dir],
diff --git a/src/Makefile.am b/src/Makefile.am
index c43fba0..8999673 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -1,3 +1,4 @@
+AM_CFLAGS="-Wall"
 bin_PROGRAMS = tio
 tio_SOURCES = tty.c \
               options.c \