diff --git a/fish-rust/src/topic_monitor.rs b/fish-rust/src/topic_monitor.rs
index d2d6ae23e..81fd3894c 100644
--- a/fish-rust/src/topic_monitor.rs
+++ b/fish-rust/src/topic_monitor.rs
@@ -24,8 +24,8 @@ use crate::fd_readable_set::fd_readable_set_t;
 use crate::fds::{self, AutoClosePipes};
 use crate::ffi::{self as ffi, c_int};
 use crate::flog::{FloggableDebug, FLOG};
-use crate::wchar::{widestrs, wstr, WString};
-use crate::wchar_ffi::wcharz;
+use crate::wchar::WString;
+use crate::wutil::perror;
 use nix::errno::Errno;
 use nix::unistd;
 use std::cell::UnsafeCell;
@@ -88,7 +88,6 @@ pub fn all_topics() -> [topic_t; 3] {
     [topic_t::sighupint, topic_t::sigchld, topic_t::internal_exit]
 }
 
-#[widestrs]
 impl generation_list_t {
     pub fn new() -> Self {
         Self::default()
@@ -225,14 +224,13 @@ impl binary_semaphore_t {
     }
 
     /// Release a waiting thread.
-    #[widestrs]
     pub fn post(&self) {
         // Beware, we are in a signal handler.
         if self.sem_ok_ {
             let res = unsafe { libc::sem_post(self.sem_.get()) };
             // sem_post is non-interruptible.
             if res < 0 {
-                self.die("sem_post"L);
+                self.die("sem_post");
             }
         } else {
             // Write exactly one byte.
@@ -247,14 +245,13 @@ impl binary_semaphore_t {
                 break;
             }
             if !success {
-                self.die("write"L);
+                self.die("write");
             }
         }
     }
 
     /// Wait for a post.
     /// This loops on EINTR.
-    #[widestrs]
     pub fn wait(&self) {
         if self.sem_ok_ {
             let mut res;
@@ -267,7 +264,7 @@ impl binary_semaphore_t {
             }
             // Other errors here are very unexpected.
             if res < 0 {
-                self.die("sem_wait"L);
+                self.die("sem_wait");
             }
         } else {
             let fd = self.pipes_.read.fd();
@@ -288,14 +285,14 @@ impl binary_semaphore_t {
                 if amt.is_err()
                     && (amt.err() != Some(Errno::EINTR) && amt.err() != Some(Errno::EAGAIN))
                 {
-                    self.die("read"L);
+                    self.die("read");
                 }
             }
         }
     }
 
-    pub fn die(&self, msg: &wstr) {
-        ffi::wperror(wcharz!(msg));
+    pub fn die(&self, msg: &str) {
+        perror(msg);
         panic!("die");
     }
 }