diff --git a/src/Makefile.am b/src/Makefile.am
index 65415ee..b6826ea 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -9,4 +9,4 @@
 
 libosmocore_la_SOURCES = msgb.c timer.c talloc.c select.c signal.c \
 			 tlv_parser.c bitvec.c comp128.c gsm_utils.c statistics.c \
-			 write_queue.c utils.c rsl.c
+			 write_queue.c utils.c rsl.c gsm48.c