diff --git a/notmuch-index-message.cc b/notmuch-index-message.cc
index 4585a3b9..efc7eb14 100644
--- a/notmuch-index-message.cc
+++ b/notmuch-index-message.cc
@@ -204,6 +204,9 @@ gen_terms_address_names (Xapian::TermGenerator term_gen,
     int i;
     InternetAddress *address;
 
+    if (addresses == NULL)
+	return;
+
     for (i = 0; i < internet_address_list_length (addresses); i++) {
 	address = internet_address_list_get_address (addresses, i);
 	gen_terms_address_name (term_gen, address, address_type);
@@ -234,6 +237,9 @@ add_terms_address_addrs (Xapian::Document doc,
     int i;
     InternetAddress *address;
 
+    if (addresses == NULL)
+	return;
+
     for (i = 0; i < internet_address_list_length (addresses); i++) {
 	address = internet_address_list_get_address (addresses, i);
 	add_term_address_addr (doc, address, address_type);