diff --git a/crates/sys/src/functions.rs b/crates/sys/src/functions.rs
index 3041d1e4..372f8705 100644
--- a/crates/sys/src/functions.rs
+++ b/crates/sys/src/functions.rs
@@ -487,10 +487,13 @@ mod napi1 {
 #[cfg(feature = "napi2")]
 mod napi2 {
   use super::super::types::*;
+  use std::os::raw::c_int;
 
   generate!(
     extern "C" {
       fn napi_get_uv_event_loop(env: napi_env, loop_: *mut *mut uv_loop_s) -> napi_status;
+
+      fn uv_run(loop_: *mut uv_loop_s, mode: uv_run_mode) -> c_int;
     }
   );
 }
diff --git a/crates/sys/src/types.rs b/crates/sys/src/types.rs
index 4eda84e8..27ea384e 100644
--- a/crates/sys/src/types.rs
+++ b/crates/sys/src/types.rs
@@ -55,6 +55,13 @@ pub struct napi_deferred__ {
 pub struct uv_loop_s {
   _unused: [u8; 0],
 }
+#[repr(C)]
+#[derive(Copy, Clone)]
+pub enum uv_run_mode {
+  UV_RUN_DEFAULT = 0,
+  UV_RUN_ONCE = 1,
+  UV_RUN_NOWAIT = 2,
+}
 pub type napi_deferred = *mut napi_deferred__;
 
 pub type napi_property_attributes = i32;