diff --git a/libmctp-sizes.h.in b/libmctp-sizes.h.in
index cbca7a9..f921c51 100644
--- a/libmctp-sizes.h.in
+++ b/libmctp-sizes.h.in
@@ -1,3 +1,5 @@
 #pragma once
 
 #define MCTP_SIZEOF_STRUCT_MCTP @sizeof_struct_mctp@
+/* sizeof(struct mctp_binding_i2c) */
+#define MCTP_SIZEOF_BINDING_I2C @sizeof_binding_i2c@