diff --git a/doc/man7/notmuch-sexp-queries.rst b/doc/man7/notmuch-sexp-queries.rst
index d28f40bb..422154c7 100644
--- a/doc/man7/notmuch-sexp-queries.rst
+++ b/doc/man7/notmuch-sexp-queries.rst
@@ -125,6 +125,9 @@ bounds. Either upper or lower bound may be specified as ``""`` or
 ``*`` to specify the lowest possible lower bound or highest possible
 upper bound.
 
+``lastmod`` ranges support negative arguments, interpreted relative to
+the most recent database revision (see :option:`count --lastmod`).
+
 .. _field-table:
 
 .. table:: Fields with supported modifiers
diff --git a/lib/parse-sexp.cc b/lib/parse-sexp.cc
index 0f14d8b7..e9ef4268 100644
--- a/lib/parse-sexp.cc
+++ b/lib/parse-sexp.cc
@@ -575,6 +575,9 @@ _sexp_parse_range (notmuch_database_t *notmuch,  const _sexp_prefix_t *prefix,
 	    return NOTMUCH_STATUS_BAD_QUERY_SYNTAX;
 	}
 
+	if (from_idx < 0)
+	    from_idx += notmuch_database_get_revision (notmuch, NULL);
+
 	try {
 	    if (EMPTY_STRING (to))
 		to_idx = LONG_MAX;
@@ -585,6 +588,9 @@ _sexp_parse_range (notmuch_database_t *notmuch,  const _sexp_prefix_t *prefix,
 	    return NOTMUCH_STATUS_BAD_QUERY_SYNTAX;
 	}
 
+	if (to_idx < 0)
+	    to_idx += notmuch_database_get_revision (notmuch, NULL);
+
 	output = Xapian::Query (Xapian::Query::OP_VALUE_RANGE, NOTMUCH_VALUE_LAST_MOD,
 				Xapian::sortable_serialise (from_idx),
 				Xapian::sortable_serialise (to_idx));
diff --git a/test/T081-sexpr-search.sh b/test/T081-sexpr-search.sh
index ce6b11b6..0c7db9c2 100755
--- a/test/T081-sexpr-search.sh
+++ b/test/T081-sexpr-search.sh
@@ -934,6 +934,14 @@ notmuch search lastmod:$revision..$revision | notmuch_search_sanitize > EXPECTED
 notmuch search --query=sexp  "(and (lastmod $revision))" | notmuch_search_sanitize > OUTPUT
 test_expect_equal_file EXPECTED OUTPUT
 
+test_begin_subtest "lastmod query, one argument (negative)"
+notmuch tag +4EFC743A.3060609@april.org id:4EFC743A.3060609@april.org
+revision=$(notmuch count --lastmod '*' | cut -f3)
+revision1=$((revision - 1))
+notmuch search lastmod:$revision1..$revision1 | notmuch_search_sanitize > EXPECTED
+notmuch search --query=sexp  "(lastmod -1)" | notmuch_search_sanitize > OUTPUT
+test_expect_equal_file_nonempty EXPECTED OUTPUT
+
 test_begin_subtest "lastmod query, two arguments"
 notmuch tag +keithp from:keithp
 revision2=$(notmuch count --lastmod '*' | cut -f3)
@@ -941,16 +949,38 @@ notmuch search lastmod:$revision..$revision2 | notmuch_search_sanitize > EXPECTE
 notmuch search --query=sexp  "(and (lastmod $revision $revision2))" | notmuch_search_sanitize > OUTPUT
 test_expect_equal_file EXPECTED OUTPUT
 
+test_begin_subtest "lastmod query, two arguments, first negative"
+revdiff=$((revision2 - revision))
+notmuch search lastmod:$revision..$revision2 | notmuch_search_sanitize > EXPECTED
+notmuch search --query=sexp  "(lastmod -$revdiff $revision2)" | notmuch_search_sanitize > OUTPUT
+test_expect_equal_file EXPECTED OUTPUT
+
+test_begin_subtest "lastmod query, two arguments, second negative"
+revdiff=$((revision2 - revision))
+notmuch search lastmod:..$revision | notmuch_search_sanitize > EXPECTED
+notmuch search --query=sexp  "(lastmod 0 -$revdiff)" | notmuch_search_sanitize > OUTPUT
+test_expect_equal_file EXPECTED OUTPUT
+
 test_begin_subtest "lastmod query, lower bound only"
 notmuch search lastmod:$revision.. | notmuch_search_sanitize > EXPECTED
 notmuch search --query=sexp  "(lastmod $revision \"\")" | notmuch_search_sanitize > OUTPUT
 test_expect_equal_file_nonempty EXPECTED OUTPUT
 
+test_begin_subtest "lastmod query, lower bound only (negative)"
+notmuch search lastmod:$revision.. | notmuch_search_sanitize > EXPECTED
+notmuch search --query=sexp  "(lastmod -$revdiff \"\")" | notmuch_search_sanitize > OUTPUT
+test_expect_equal_file_nonempty EXPECTED OUTPUT
+
 test_begin_subtest "lastmod query, upper bound only"
 notmuch search lastmod:..$revision2 | notmuch_search_sanitize > EXPECTED
 notmuch search --query=sexp  "(lastmod \"\" $revision2)" | notmuch_search_sanitize > OUTPUT
 test_expect_equal_file_nonempty EXPECTED OUTPUT
 
+test_begin_subtest "lastmod query, upper bound only (negative)"
+notmuch search lastmod:..$revision | notmuch_search_sanitize > EXPECTED
+notmuch search --query=sexp  "(lastmod \"\" -$revdiff)" | notmuch_search_sanitize > OUTPUT
+test_expect_equal_file_nonempty EXPECTED OUTPUT
+
 test_begin_subtest "lastmod query, lower bound only, using *"
 notmuch search lastmod:$revision.. | notmuch_search_sanitize > EXPECTED
 notmuch search --query=sexp  "(lastmod $revision *)" | notmuch_search_sanitize > OUTPUT
diff --git a/test/T570-revision-tracking.sh b/test/T570-revision-tracking.sh
index e1cc684d..aaa45468 100755
--- a/test/T570-revision-tracking.sh
+++ b/test/T570-revision-tracking.sh
@@ -95,4 +95,12 @@ subtotal=$(notmuch count lastmod:..$lastmod)
 result=$(($subtotal == $total-1))
 test_expect_equal 1 "$result"
 
+if [ $NOTMUCH_HAVE_SFSEXP -eq 1 ]; then
+    test_begin_subtest 'exclude one message using negative lastmod (sexp)'
+    total=$(notmuch count '*')
+    notmuch tag +${RANDOM} id:4EFC743A.3060609@april.org
+    count=$(notmuch count --query=sexp '(lastmod -1 *)')
+    test_expect_equal 1 "$count"
+fi
+
 test_done