diff --git a/src/tbf_ul.h b/src/tbf_ul.h
index d5cfbd5..826062f 100644
--- a/src/tbf_ul.h
+++ b/src/tbf_ul.h
@@ -137,6 +137,7 @@
 void set_tbf_ta(struct gprs_rlcmac_ul_tbf *tbf, uint8_t ta);
 struct gprs_rlcmac_ul_tbf *as_ul_tbf(struct gprs_rlcmac_tbf *tbf);
 void tbf_usf_timeout(struct gprs_rlcmac_ul_tbf *tbf);
+bool ul_tbf_contention_resolution_done(const struct gprs_rlcmac_ul_tbf *tbf);
 
 #define LOGPTBFUL(tbf, level, fmt, args...) LOGP(DTBFUL, level, "%s " fmt, tbf_name(tbf), ## args)
 #ifdef __cplusplus