diff --git a/test-env.in b/test-env.in
index 64440fb86a..e6b13c271e 100644
--- a/test-env.in
+++ b/test-env.in
@@ -56,6 +56,10 @@ then
     # Do that because store.scm calls `canonicalize-path' on it.
     mkdir -p "$NIX_STORE_DIR"
 
+    # Set the umask to avoid "suspicious ownership or permission" errors.
+    # See <http://lists.gnu.org/archive/html/bug-guix/2013-07/msg00033.html>.
+    umask 0022
+
     # Launch the daemon without chroot support because is may be
     # unavailable, for instance if we're not running as root.
     "@abs_top_builddir@/pre-inst-env"				\