diff --git a/include/osmocom/gapk/procqueue.h b/include/osmocom/gapk/procqueue.h
index a72fd61..9b049a5 100644
--- a/include/osmocom/gapk/procqueue.h
+++ b/include/osmocom/gapk/procqueue.h
@@ -40,6 +40,7 @@ struct osmo_gapk_pq_item {
 	 *  \param[in] in_len length of input data \a in
 	 *  \returns number of output bytes written to \a out; negative on error */
 	int  (*proc)(void *state, uint8_t *out, const uint8_t *in, unsigned int in_len);
+	int  (*wait)(void *state);
 	void (*exit)(void *state);
 
 	/*! \brief link to a processing queue */
diff --git a/src/pq_alsa.c b/src/pq_alsa.c
index b91457e..779dd96 100644
--- a/src/pq_alsa.c
+++ b/src/pq_alsa.c
@@ -138,6 +138,7 @@ pq_queue_alsa_op(struct osmo_gapk_pq *pq, const char *alsa_dev, unsigned int blk
 	item->len_out = in_out_n ? blk_len : 0;
 	item->state   = state;
 	item->proc    = in_out_n ? pq_cb_alsa_input : pq_cb_alsa_output;
+	item->wait    = NULL;
 	item->exit    = pq_cb_alsa_exit;
 
 	return 0;
diff --git a/src/pq_codec.c b/src/pq_codec.c
index f5da628..e033a7d 100644
--- a/src/pq_codec.c
+++ b/src/pq_codec.c
@@ -71,6 +71,7 @@ osmo_gapk_pq_queue_codec(struct osmo_gapk_pq *pq, const struct osmo_gapk_codec_d
 	}
 
 	item->exit = codec->codec_exit;
+	item->wait = NULL;
 
 	LOGPGAPK(LOGL_DEBUG, "PQ: Adding codec %s, %s format %s\n", codec->name,
 		enc_dec_n ? "encoding to" : "decoding from", fmt->name);
diff --git a/src/pq_file.c b/src/pq_file.c
index b31ef52..d05f82a 100644
--- a/src/pq_file.c
+++ b/src/pq_file.c
@@ -83,6 +83,7 @@ pq_queue_file_op(struct osmo_gapk_pq *pq, FILE *fh, unsigned int blk_len, int in
 	item->len_out = in_out_n ? blk_len : 0;
 	item->state   = state;
 	item->proc    = in_out_n ? pq_cb_file_input : pq_cb_file_output;
+	item->wait    = NULL;
 	item->exit    = pq_cb_file_exit;
 
 	return 0;
diff --git a/src/pq_format.c b/src/pq_format.c
index ae5386e..8ea8b86 100644
--- a/src/pq_format.c
+++ b/src/pq_format.c
@@ -70,6 +70,7 @@ osmo_gapk_pq_queue_fmt_convert(struct osmo_gapk_pq *pq, const struct osmo_gapk_f
 	}
 
 	item->proc = pq_cb_fmt_convert;
+	item->wait = NULL;
 
 	return 0;
 }
diff --git a/src/pq_rtp.c b/src/pq_rtp.c
index 6e7a87d..1c37475 100644
--- a/src/pq_rtp.c
+++ b/src/pq_rtp.c
@@ -229,6 +229,7 @@ pq_queue_rtp_op(struct osmo_gapk_pq *pq, int udp_fd, unsigned int blk_len, int i
 	item->len_out = in_out_n ? blk_len : 0;
 	item->state   = state;
 	item->proc    = in_out_n ? pq_cb_rtp_input : pq_cb_rtp_output;
+	item->wait    = NULL;
 	item->exit    = pq_cb_rtp_exit;
 
 	return 0;