diff --git a/openbsc/src/libmgcp/Makefile.am b/openbsc/src/libmgcp/Makefile.am
index d02b880..4403d60 100644
--- a/openbsc/src/libmgcp/Makefile.am
+++ b/openbsc/src/libmgcp/Makefile.am
@@ -8,7 +8,8 @@
 
 noinst_HEADERS = g711common.h
 
-libmgcp_a_SOURCES = mgcp_protocol.c mgcp_network.c mgcp_vty.c mgcp_osmux.c
+libmgcp_a_SOURCES = mgcp_protocol.c mgcp_network.c mgcp_vty.c mgcp_osmux.c \
+	mgcp_sdp.c
 
 if BUILD_MGCP_TRANSCODING
     libmgcp_a_SOURCES += mgcp_transcode.c