diff --git a/test/hex-escaping b/test/hex-escaping
new file mode 100755
index 00000000..ad50e1bc
--- /dev/null
+++ b/test/hex-escaping
@@ -0,0 +1,50 @@
+#!/usr/bin/env bash
+test_description="hex encoding and decoding"
+. ./test-lib.sh
+
+test_begin_subtest "round trip"
+find $TEST_DIRECTORY/corpus -type f -print | sort | xargs cat > EXPECTED
+$TEST_DIRECTORY/hex-xcode --direction=encode < EXPECTED | $TEST_DIRECTORY/hex-xcode --direction=decode > OUTPUT
+test_expect_equal_file OUTPUT EXPECTED
+
+test_begin_subtest "punctuation"
+tag1='comic_swear=$&^%$^%\\//-+$^%$'
+tag_enc1=$($TEST_DIRECTORY/hex-xcode --direction=encode "$tag1")
+test_expect_equal "$tag_enc1" "comic_swear=%24%26%5e%25%24%5e%25%5c%5c%2f%2f-+%24%5e%25%24"
+
+test_begin_subtest "round trip newlines"
+printf 'this\n tag\t has\n spaces\n' > EXPECTED.$test_count
+$TEST_DIRECTORY/hex-xcode --direction=encode  < EXPECTED.$test_count |\
+	$TEST_DIRECTORY/hex-xcode --direction=decode > OUTPUT.$test_count
+test_expect_equal_file EXPECTED.$test_count OUTPUT.$test_count
+
+test_begin_subtest "round trip 8bit chars"
+echo '%c3%91%c3%a5%c3%b0%c3%a3%c3%a5%c3%a9-%c3%8f%c3%8a' > EXPECTED.$test_count
+$TEST_DIRECTORY/hex-xcode --direction=decode  < EXPECTED.$test_count |\
+    $TEST_DIRECTORY/hex-xcode --direction=encode > OUTPUT.$test_count
+test_expect_equal_file EXPECTED.$test_count OUTPUT.$test_count
+
+test_begin_subtest "round trip (in-place)"
+find $TEST_DIRECTORY/corpus -type f -print | sort | xargs cat > EXPECTED
+$TEST_DIRECTORY/hex-xcode --in-place --direction=encode < EXPECTED |\
+     $TEST_DIRECTORY/hex-xcode --in-place --direction=decode > OUTPUT
+test_expect_equal_file OUTPUT EXPECTED
+
+test_begin_subtest "punctuation (in-place)"
+tag1='comic_swear=$&^%$^%\\//-+$^%$'
+tag_enc1=$($TEST_DIRECTORY/hex-xcode --in-place --direction=encode "$tag1")
+test_expect_equal "$tag_enc1" "comic_swear=%24%26%5e%25%24%5e%25%5c%5c%2f%2f-+%24%5e%25%24"
+
+test_begin_subtest "round trip newlines (in-place)"
+printf 'this\n tag\t has\n spaces\n' > EXPECTED.$test_count
+$TEST_DIRECTORY/hex-xcode --in-place --direction=encode  < EXPECTED.$test_count |\
+    $TEST_DIRECTORY/hex-xcode --in-place --direction=decode > OUTPUT.$test_count
+test_expect_equal_file EXPECTED.$test_count OUTPUT.$test_count
+
+test_begin_subtest "round trip 8bit chars (in-place)"
+echo '%c3%91%c3%a5%c3%b0%c3%a3%c3%a5%c3%a9-%c3%8f%c3%8a' > EXPECTED.$test_count
+$TEST_DIRECTORY/hex-xcode --in-place --direction=decode  < EXPECTED.$test_count |\
+    $TEST_DIRECTORY/hex-xcode --in-place --direction=encode > OUTPUT.$test_count
+test_expect_equal_file EXPECTED.$test_count OUTPUT.$test_count
+
+test_done
diff --git a/test/notmuch-test b/test/notmuch-test
index f2754398..a6ef34fe 100755
--- a/test/notmuch-test
+++ b/test/notmuch-test
@@ -60,6 +60,7 @@ TESTS="
   emacs-hello
   emacs-show
   missing-headers
+  hex-escaping
   parse-time-string
   search-date
 "