diff --git a/src/lib-storage/index/index-mail-headers.c b/src/lib-storage/index/index-mail-headers.c
index 7e3753f3e6..f02bfe6423 100644
--- a/src/lib-storage/index/index-mail-headers.c
+++ b/src/lib-storage/index/index-mail-headers.c
@@ -315,7 +315,7 @@ void index_mail_parse_header(struct message_part *part,
 		if (data->save_bodystructure_header) {
 			i_assert(!data->save_bodystructure_body ||
 				 data->parser_ctx != NULL);
-			data->save_bodystructure_header = FALSE;
+			data->parsed_bodystructure_header = TRUE;
 		}
 		return;
 	}
@@ -416,6 +416,12 @@ static void index_mail_init_parser(struct index_mail *mail)
 			index_mail_set_message_parts_corrupted(&mail->mail.mail, error);
 			data->parts = NULL;
 		}
+		if (data->parts == NULL) {
+			/* The previous parsing didn't finish, so we're
+			   re-parsing the header. The new parts don't have data
+			   filled anymore. */
+			data->parsed_bodystructure_header = FALSE;
+		}
 	}
 
 	if (data->parts == NULL) {
diff --git a/src/lib-storage/index/index-mail.c b/src/lib-storage/index/index-mail.c
index c520cfdf73..46a6cb2113 100644
--- a/src/lib-storage/index/index-mail.c
+++ b/src/lib-storage/index/index-mail.c
@@ -1182,7 +1182,7 @@ static int index_mail_parse_body(struct index_mail *mail,
 	if (data->save_bodystructure_body) {
 		/* bodystructure header is parsed, we want the body's mime
 		   headers too */
-		i_assert(!data->save_bodystructure_header);
+		i_assert(data->parsed_bodystructure_header);
 		message_parser_parse_body(data->parser_ctx,
 					  parse_bodystructure_part_header,
 					  mail->mail.data_pool);
@@ -1327,7 +1327,8 @@ static int index_mail_parse_bodystructure(struct index_mail *mail,
 		   a string */
 		index_mail_body_parsed_cache_bodystructure(mail, field);
 	} else {
-		if (data->save_bodystructure_header ||
+		if ((data->save_bodystructure_header &&
+		     !data->parsed_bodystructure_header) ||
 		    !data->save_bodystructure_body ||
 		    field == MAIL_CACHE_BODY_SNIPPET) {
 			/* we haven't parsed the header yet */
diff --git a/src/lib-storage/index/index-mail.h b/src/lib-storage/index/index-mail.h
index 9dc652cdcf..c4994f031a 100644
--- a/src/lib-storage/index/index-mail.h
+++ b/src/lib-storage/index/index-mail.h
@@ -118,6 +118,7 @@ struct index_mail_data {
 	unsigned int save_body_snippet:1;
 	unsigned int stream_has_only_header:1;
 	unsigned int parsed_bodystructure:1;
+	unsigned int parsed_bodystructure_header:1;
 	unsigned int hdr_size_set:1;
 	unsigned int body_size_set:1;
 	unsigned int messageparts_saved_to_cache:1;