diff --git a/src/gsm/libosmogsm.map b/src/gsm/libosmogsm.map
index 031cc20..f339120 100644
--- a/src/gsm/libosmogsm.map
+++ b/src/gsm/libosmogsm.map
@@ -339,6 +339,7 @@
 gsm48_decode_connected;
 gsm48_decode_facility;
 gsm48_decode_freq_list;
+gsm48_decode_classmark3;
 gsm48_decode_keypad;
 gsm48_decode_lai;
 gsm48_decode_notify;