diff --git a/urchin b/urchin
index bf2017c..58deede 100755
--- a/urchin
+++ b/urchin
@@ -283,7 +283,7 @@ urchin_root() {
 
   abscurrent="$(fullpath "${1}")"
   if test "${abscurrent}" = / ||
-    basename "${abscurrent}" | grep -q '^\.' ; then
+    basename "${abscurrent}" | contains '^\.' ; then
     # Stop traversing upwards at / and at hidden directories.
     if test -d "${orig}"; then
       echo "${orig}"
@@ -315,8 +315,8 @@ recurse() {
     fi
   done
 
-  if contains "${potential_test}" "^${potential_test}" ||
-     contains "${potential_test}" "^${requested_path}" ; then
+  if contains "${potential_test}" \
+    "^${potential_test}" "^${requested_path}" ; then
     if test "$(dirname "${potential_test}")" = \
             "$(dirname "${requested_path}")" &&
        test "${potential_test}" != "${requested_path}"; then
@@ -335,7 +335,7 @@ recurse() {
     if [ -d "${potential_test}" ]; then
     (
       cd -- "${potential_test}"
-      if test -f .urchin_dir && grep -q series .urchin_dir ; then
+      if test -f .urchin_dir && grep series .urchin_dir > /dev/null; then
         run_in_series_dir=true
       else
         run_in_series_dir=false
@@ -670,7 +670,7 @@ validate_test_arg() {
   root="$(urchin_root "${1}")"
   if ! {
     basename "$(fullpath "${root}")" |
-    grep -qi 'test' || "${force}"
+    grep -i 'test' > /dev/null || "${force}"
   }; then
     echo 'The root directory of the tests that you are running urchin on
   does not contain the word "test", so I am not running,