clarify grep version
diff --git a/testsuite/grep.tests b/testsuite/grep.tests
index 4703ae5..34c0fe4 100755
--- a/testsuite/grep.tests
+++ b/testsuite/grep.tests
@@ -26,7 +26,7 @@
testing "grep input (specify file)" "grep two input" "two\n" \
"one\ntwo\nthree\nthree\nthree\n" ""
-# GNU grep (version?) outputs a new line character after the located string
+# GNU grep 2.5.3 outputs a new line character after the located string
# even if there is no new line character in the input
testing "grep (no newline at EOL)" "grep bug input" "bug\n" "bug" ""