diff --git a/ref-filter.c b/ref-filter.c
index 0f5513ba7e..e39f505a81 100644
--- a/ref-filter.c
+++ b/ref-filter.c
@@ -2008,9 +2008,17 @@ static void grab_sub_body_contents(struct atom_value *val, int deref, struct exp
 			v->s = strbuf_detach(&s, NULL);
 		} else if (atom->u.contents.option == C_TRAILERS) {
 			struct strbuf s = STRBUF_INIT;
+			const char *msg;
+			char *to_free = NULL;
+
+			if (siglen)
+				msg = to_free = xmemdupz(subpos, sigpos - subpos);
+			else
+				msg = subpos;
 
 			/* Format the trailer info according to the trailer_opts given */
-			format_trailers_from_commit(&atom->u.contents.trailer_opts, subpos, &s);
+			format_trailers_from_commit(&atom->u.contents.trailer_opts, msg, &s);
+			free(to_free);
 
 			v->s = strbuf_detach(&s, NULL);
 		} else if (atom->u.contents.option == C_BARE)
diff --git a/t/t6300-for-each-ref.sh b/t/t6300-for-each-ref.sh
index 7c208e20a6..b830b542c4 100755
--- a/t/t6300-for-each-ref.sh
+++ b/t/t6300-for-each-ref.sh
@@ -1835,6 +1835,24 @@ sig_crlf="$(printf "%s" "$sig" | append_cr; echo dummy)"
 sig_crlf=${sig_crlf%dummy}
 test_atom refs/tags/fake-sig-crlf contents:signature "$sig_crlf"
 
+test_expect_success 'set up tag with signature and trailers' '
+	git tag -F - fake-sig-trailer <<-\EOF
+	this is the subject
+
+	this is the body
+
+	My-Trailer: foo
+	-----BEGIN PGP SIGNATURE-----
+
+	not a real signature, but we just care about the
+	subject/body/trailer parsing.
+	-----END PGP SIGNATURE-----
+	EOF
+'
+
+# use "separator=" here to suppress the terminating newline
+test_atom refs/tags/fake-sig-trailer trailers:separator= 'My-Trailer: foo'
+
 test_expect_success 'git for-each-ref --stdin: empty' '
 	>in &&
 	git for-each-ref --format="%(refname)" --stdin <in >actual &&