--- test/mhshow/test-binary.orig	2023-12-04 03:00:44 UTC
+++ test/mhshow/test-binary
@@ -21,7 +21,7 @@ expected="$MH_TEST_DIR/test-binary$$.expected"
 
 #### Use the printf to output the NUL byte so that this
 #### file (test-binary) doesn't need to be a binary file.
-printf '%s\000%s' >"${expected}" \
+printf '%s\x00%s' >"${expected}" \
 "[ Message inbox:11 ]
 To:      recipient@example.edu
 From:    sender@example.edu
@@ -33,7 +33,7 @@ Here's a null byte: " ".
 Here's a null byte: " ".
 "
 
-printf '%s\000%s' >`mhpath new` \
+printf '%s\x00%s' >`mhpath new` \
 "From: sender@example.edu
 To: recipient@example.edu
 Subject: test binary content