diff --git a/sphinx-ffi/src/auto.rs b/sphinx-ffi/src/auto.rs
index b3d3ad2..3af8c7f 100644
--- a/sphinx-ffi/src/auto.rs
+++ b/sphinx-ffi/src/auto.rs
@@ -569,7 +569,7 @@ pub fn fetch_payments(
     seed: String,
     unique_time: String,
     full_state: Vec<u8>,
-    last_msg_idx: Option<u64>,
+    since: Option<u64>,
     limit: Option<u32>,
     scid: Option<u64>,
     remote_only: Option<bool>,
@@ -579,7 +579,7 @@ pub fn fetch_payments(
         &seed,
         &unique_time,
         &full_state,
-        last_msg_idx,
+        since,
         limit,
         scid,
         remote_only,
diff --git a/sphinx-ffi/src/sphinxrs.udl b/sphinx-ffi/src/sphinxrs.udl
index 442b957..26c2715 100644
--- a/sphinx-ffi/src/sphinxrs.udl
+++ b/sphinx-ffi/src/sphinxrs.udl
@@ -210,5 +210,5 @@ namespace sphinxrs {
   [Throws=SphinxError]
   RunReturn fetch_first_msgs_per_key(string seed, string unique_time, bytes state, u64 last_msg_idx, u32? limit, boolean? reverse);
   [Throws=SphinxError]
-  RunReturn fetch_payments(string seed, string unique_time, bytes state, u64? last_msg_idx, u32? limit, u64? scid, boolean? remote_only, u64? min_msat);
+  RunReturn fetch_payments(string seed, string unique_time, bytes state, u64? since, u32? limit, u64? scid, boolean? remote_only, u64? min_msat);
 };
\ No newline at end of file