diff --git a/include/types/proto_http.h b/include/types/proto_http.h
index 2654b78..d9cda71 100644
--- a/include/types/proto_http.h
+++ b/include/types/proto_http.h
@@ -438,6 +438,9 @@
 			struct list key;       /* pattern to retrieve MAP or ACL key */
 			struct list value;     /* pattern to retrieve MAP value */
 		} map;
+		struct {
+			void *p[4];
+		} act;                         /* generic pointers to be used by custom actions */
 	} arg;                                 /* arguments used by some actions */
 
 	union {