diff --git a/daemon/json.c b/daemon/json.c
index f6c3d75a8..3b5109856 100644
--- a/daemon/json.c
+++ b/daemon/json.c
@@ -6,6 +6,7 @@
 #include <ccan/tal/str/str.h>
 #include <ccan/tal/tal.h>
 #include <errno.h>
+#include <inttypes.h>
 #include <stdarg.h>
 #include <stdio.h>
 #include <string.h>
@@ -357,6 +358,13 @@ void json_add_num(struct json_result *result, const char *fieldname, unsigned in
 	result_append_fmt(result, "%u", value);
 }
 
+void json_add_u64(struct json_result *result, const char *fieldname,
+		  uint64_t value)
+{
+	json_start_member(result, fieldname);
+	result_append_fmt(result, "%"PRIu64, value);
+}
+	
 void json_add_literal(struct json_result *result, const char *fieldname,
 		      const char *literal, int len)
 {
diff --git a/daemon/json.h b/daemon/json.h
index 68347d68a..48e6c159f 100644
--- a/daemon/json.h
+++ b/daemon/json.h
@@ -81,6 +81,9 @@ void json_add_literal(struct json_result *result, const char *fieldname,
 /* '"fieldname" : value' or 'value' if fieldname is NULL */
 void json_add_num(struct json_result *result, const char *fieldname,
 		  unsigned int value);
+/* '"fieldname" : value' or 'value' if fieldname is NULL */
+void json_add_u64(struct json_result *result, const char *fieldname,
+		  uint64_t value);
 /* '"fieldname" : true|false' or 'true|false' if fieldname is NULL */
 void json_add_bool(struct json_result *result, const char *fieldname,
 		   bool value);