diff --git a/src/rua/Makefile.am b/src/rua/Makefile.am
index c93b801..cb13a1c 100644
--- a/src/rua/Makefile.am
+++ b/src/rua/Makefile.am
@@ -72,7 +72,7 @@
 	RUA_PrivateMessage.h	\
 	RUA_IE.h
 
-AM_CFLAGS = $(ASN1C_CFLAGS) -I.
+AM_CFLAGS = $(ASN1C_CFLAGS) $(OSMOCORE_CFLAGS) -I.
 
 noinst_LIBRARIES=libosmo-asn1-rua.a
 libosmo_asn1_rua_a_SOURCES=$(ASN_MODULE_SOURCES)