diff --git a/openbsc/src/libcommon/socket.c b/openbsc/src/libcommon/socket.c
index 6c47a8d..2a64767 100644
--- a/openbsc/src/libcommon/socket.c
+++ b/openbsc/src/libcommon/socket.c
@@ -54,9 +54,11 @@
 	case IPPROTO_UDP:
 		type = SOCK_DGRAM;
 		break;
+#ifdef IPPROTO_GRE
 	case IPPROTO_GRE:
 		type = SOCK_RAW;
 		break;
+#endif
 	default:
 		return -EINVAL;
 	}