diff --git a/tests/t1900-archive.sh b/tests/t1900-archive.sh
new file mode 100755
index 0000000..5ac9316
--- /dev/null
+++ b/tests/t1900-archive.sh
@@ -0,0 +1,34 @@
+#!/bin/sh
+
+test_description='archive functionality
+
+Ensure we can append items successfully.
+'
+. ./test-lib.sh
+
+cat >> todo.txt<<EOF
+one
+two
+three
+one
+x done
+four
+EOF
+
+test_todo_session 'archive with duplicates' <<EOF
+>>> todo.sh archive
+x done
+TODO: $HOME/todo.txt archived.
+EOF
+
+test_todo_session 'list after archive' <<EOF
+>>> todo.sh ls
+4 four
+1 one
+3 three
+2 two
+--
+TODO: 4 of 4 tasks shown
+EOF
+
+test_done
diff --git a/todo.sh b/todo.sh
index 337bbea..f945fa6 100755
--- a/todo.sh
+++ b/todo.sh
@@ -371,7 +371,7 @@ archive()
     grep "^x " "$TODO_FILE" >> "$DONE_FILE"
     sed -i.bak '/^x /d' "$TODO_FILE"
     cp "$TODO_FILE" "$TMP_FILE"
-    sed -n 'G; s/\n/&&/; /^\([ ~-]*\n\).*\n\1/d; s/\n//; h; P' "$TMP_FILE" > "$TODO_FILE"
+    sed -n 'G; s/\n/&&/; /^\([ -~]*\n\).*\n\1/d; s/\n//; h; P' "$TMP_FILE" > "$TODO_FILE"
     if [ $TODOTXT_VERBOSE -gt 0 ]; then
 	echo "TODO: $TODO_FILE archived."
     fi