diff --git a/build.spec b/build.spec
index 3520aa2..fdd25cd 100644
--- a/build.spec
+++ b/build.spec
@@ -205,7 +205,7 @@ test -e baselibs_global.conf || exit 1
 for i in build build-* ; do bash -n $i || exit 1 ; done
 
 # expect unit tests
-LANG=C prove -I. -v t/*.t
+LANG=C prove -I. -v t/*.t || exit 1
 
 if [ `whoami` != "root" ]; then
   echo "WARNING: Not building as root, build test did not run!"