--- tests/reversed-range-endpoints
+++ tests/reversed-range-endpoints
@@ -11,7 +11,7 @@
   test $? = 2 || fail=1
 
   # Remove "program_name: " prefix from actual output.
-  sed 's/^[a-z]*: //' out > k && mv k out
+  sed 's/^[^ ]*: //' out > k && mv k out
 
   compare out exp || fail=1
 done
--- tests/warn-char-classes
+++ tests/warn-char-classes
@@ -5,13 +5,15 @@
 echo f > x || framework_failure_
 echo b >> x || framework_failure_
 echo h >> x || framework_failure_
-printf 'grep: character class syntax is [[:space:]], not [:space:]\n' \
+printf 'character class syntax is [[:space:]], not [:space:]\n' \
   > exp-err || framework_failure_
 
 # basic cases
 
 grep '[:space:]' x 2> err
 test $? = 2 || fail=1
+# Remove "program_name: " prefix from actual output.
+sed 's/^[^ ]*: //' err > k && mv k err
 compare err exp-err || fail=1
 
 grep '[[:space:]]' x 2> err