diff --git a/include/osmocom/core/gsmtap_util.h b/include/osmocom/core/gsmtap_util.h
index 5c5e3fd..f8a12a6 100644
--- a/include/osmocom/core/gsmtap_util.h
+++ b/include/osmocom/core/gsmtap_util.h
@@ -55,4 +55,7 @@
 		int8_t signal_dbm, uint8_t snr, const uint8_t *data,
 		unsigned int len);
 
+extern const struct value_string gsmtap_gsm_channel_names[];
+extern const struct value_string gsmtap_type_names[];
+
 /*! @} */