--- a/src/libpam/handle.rs	Wed Jul 16 18:45:20 2025 -0400
+++ b/src/libpam/handle.rs	Fri Jul 25 20:52:14 2025 -0400
@@ -1,6 +1,6 @@
 use super::conversation::{OwnedConversation, PamConv};
 use crate::_doc::{guide, linklist, man7, stdlinks};
-use crate::constants::{ErrorCode, Result};
+use crate::constants::{ErrorCode, RawFlags, Result, ReturnCode};
 use crate::conv::Exchange;
 use crate::environ::EnvironMapMut;
 use crate::handle::PamShared;
@@ -10,7 +10,6 @@
 use crate::libpam::{items, memory};
 use crate::logging::{Level, Location, Logger};
 use crate::{AuthnFlags, AuthtokFlags, Conversation, EnvironMap, ModuleClient, Transaction};
-use libpam_sys_consts::constants;
 use num_enum::{IntoPrimitive, TryFromPrimitive};
 use std::any::TypeId;
 use std::cell::Cell;
@@ -146,7 +145,8 @@
 
     /// Internal "end" function, which binary-ORs the status with `or_with`.
     fn end_internal(&mut self, or_with: i32) {
-        let result = ErrorCode::result_to_c(self.last_return.get()) | or_with;
+        let last: i32 = ReturnCode::from(self.last_return.get()).into();
+        let result = last | or_with;
         unsafe { libpam_sys::pam_end(self.handle.cast(), result) };
     }
 }
@@ -154,8 +154,9 @@
 macro_rules! wrap {
     (fn $name:ident($ftype:ident) { $pam_func:ident }) => {
         fn $name(&mut self, flags: $ftype) -> Result<()> {
+            let flags: RawFlags = flags.into();
             ErrorCode::result_from(unsafe {
-                libpam_sys::$pam_func((self as *mut Self).cast(), flags.bits())
+                libpam_sys::$pam_func((self as *mut Self).cast(), flags.into())
             })
         }
     };
@@ -265,7 +266,8 @@
     #[doc = guide!(adg: "adg-interface-by-app-expected.html#adg-pam_end")]
     #[doc = stdlinks!(3 pam_end)]
     pub fn end(&mut self, result: Result<()>) {
-        unsafe { libpam_sys::pam_end(self.inner_mut(), ErrorCode::result_to_c(result)) };
+        let code: ReturnCode = result.into();
+        unsafe { libpam_sys::pam_end(self.inner_mut(), code.into()) };
     }
 
     #[cfg_attr(
@@ -290,7 +292,7 @@
     #[doc = guide!(adg: "adg-interface-by-app-expected.html#adg-pam_end")]
     #[doc = stdlinks!(3 pam_end)]
     pub fn end_silent(&mut self, result: Result<()>) {
-        let result = ErrorCode::result_to_c(result);
+        let result: i32 = ReturnCode::from(result).into();
         #[cfg(pam_impl = "LinuxPam")]
         let result = result | libpam_sys::PAM_DATA_SILENT;
         unsafe {
@@ -517,33 +519,33 @@
 #[non_exhaustive] // because C could give us anything!
 pub enum ItemType {
     /// The PAM service name.
-    Service = constants::PAM_SERVICE,
+    Service = libpam_sys::PAM_SERVICE,
     /// The user's login name.
-    User = constants::PAM_USER,
+    User = libpam_sys::PAM_USER,
     /// The TTY name.
-    Tty = constants::PAM_TTY,
+    Tty = libpam_sys::PAM_TTY,
     /// The remote host (if applicable).
-    RemoteHost = constants::PAM_RHOST,
+    RemoteHost = libpam_sys::PAM_RHOST,
     /// The conversation struct (not a CStr-based item).
-    Conversation = constants::PAM_CONV,
+    Conversation = libpam_sys::PAM_CONV,
     /// The authentication token (password).
-    AuthTok = constants::PAM_AUTHTOK,
+    AuthTok = libpam_sys::PAM_AUTHTOK,
     /// The old authentication token (when changing passwords).
-    OldAuthTok = constants::PAM_OLDAUTHTOK,
+    OldAuthTok = libpam_sys::PAM_OLDAUTHTOK,
     /// The remote user's name.
-    RemoteUser = constants::PAM_RUSER,
+    RemoteUser = libpam_sys::PAM_RUSER,
     /// The prompt shown when requesting a username.
-    UserPrompt = constants::PAM_USER_PROMPT,
+    UserPrompt = libpam_sys::PAM_USER_PROMPT,
     #[cfg(feature = "linux-pam-ext")]
     /// App-supplied function to override failure delays.
-    FailDelay = constants::PAM_FAIL_DELAY,
+    FailDelay = libpam_sys::PAM_FAIL_DELAY,
     #[cfg(feature = "linux-pam-ext")]
     /// X display name.
-    XDisplay = constants::PAM_XDISPLAY,
+    XDisplay = libpam_sys::PAM_XDISPLAY,
     #[cfg(feature = "linux-pam-ext")]
     /// X server authentication data.
-    XAuthData = constants::PAM_XAUTHDATA,
+    XAuthData = libpam_sys::PAM_XAUTHDATA,
     #[cfg(feature = "linux-pam-ext")]
     /// The type of `pam_get_authtok`.
-    AuthTokType = constants::PAM_AUTHTOK_TYPE,
+    AuthTokType = libpam_sys::PAM_AUTHTOK_TYPE,
 }