diff --git a/Makefile.am b/Makefile.am
index 2cc4b91f9c456002b316270af5c966d27cfa5aaf..1a9f3af66d27971a851ab68374c41b7f7bd66131 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -19,6 +19,10 @@
 LCOV = lcov
 GENHTML = genhtml
 
+# when building from tarball -Werror isn't auto enabled
+# so force it explicitly
+DISTCHECK_CONFIGURE_FLAGS = --enable-werror
+
 SUBDIRS = . gnulib/lib include/libvirt src tools docs gnulib/tests \
   tests po examples