diff --git a/openbsc/include/osmocom/gprs/gprs_msgb.h b/openbsc/include/osmocom/gprs/gprs_msgb.h
index 3567bb7..f4c8554 100644
--- a/openbsc/include/osmocom/gprs/gprs_msgb.h
+++ b/openbsc/include/osmocom/gprs/gprs_msgb.h
@@ -31,4 +31,7 @@
 #define GPRS_CTX_NSVC	0
 #define GPRS_CTX_BVC	1
 
+#include <osmocom/core/logging.h>
+int gprs_log_filter_fn(const struct log_context *ctx,
+			struct log_target *tar);
 #endif