diff --git a/include/proto/h1.h b/include/proto/h1.h
index b722950..4463ad0 100644
--- a/include/proto/h1.h
+++ b/include/proto/h1.h
@@ -43,6 +43,7 @@
 int h1_headers_to_hdr_list(char *start, const char *stop,
                            struct http_hdr *hdr, unsigned int hdr_num,
                            struct h1m *h1m);
+int h1_measure_trailers(const struct buffer *buf);
 
 #define H1_FLG_CTL  0x01
 #define H1_FLG_SEP  0x02