diff --git a/include/osmocom/core/logging.h b/include/osmocom/core/logging.h
index 343f976..a554adc 100644
--- a/include/osmocom/core/logging.h
+++ b/include/osmocom/core/logging.h
@@ -297,8 +297,11 @@
 
 	union {
 		struct {
+			/* direct, blocking output via stdio */
 			FILE *out;
 			const char *fname;
+			/* indirect output via write_queue and osmo_select_main() */
+			struct osmo_wqueue *wqueue;
 		} tgt_file;
 
 		struct {
@@ -408,6 +411,8 @@
 struct log_target *log_target_create_systemd(bool raw);
 void log_target_systemd_set_raw(struct log_target *target, bool raw);
 int log_target_file_reopen(struct log_target *tgt);
+int log_target_file_switch_to_stream(struct log_target *tgt);
+int log_target_file_switch_to_wqueue(struct log_target *tgt);
 int log_targets_reopen(void);
 
 void log_add_target(struct log_target *target);