diff --git a/src/error.rs b/src/error.rs
index 5eff99eb..4317efd0 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -58,6 +58,8 @@ impl Error {
     pub const NODE_ES_MODULE: Error = internal_error(14);
     /// Calling Windows ProcessPrng failed.
     pub const WINDOWS_PROCESS_PRNG: Error = internal_error(15);
+    /// The mutex used when opening the random file was poisoned.
+    pub const UNEXPECTED_FILE_MUTEX_POISONED: Error = internal_error(15);
 
     /// Codes below this point represent OS Errors (i.e. positive i32 values).
     /// Codes at or above this point, but below [`Error::CUSTOM_START`] are
diff --git a/src/use_file.rs b/src/use_file.rs
index 36210dee..e42a744b 100644
--- a/src/use_file.rs
+++ b/src/use_file.rs
@@ -4,11 +4,12 @@ use crate::{
     Error,
 };
 use core::{
-    cell::UnsafeCell,
     ffi::c_void,
     mem::MaybeUninit,
     sync::atomic::{AtomicUsize, Ordering::Relaxed},
 };
+extern crate std;
+use std::sync::{Mutex, PoisonError};
 
 /// For all platforms, we use `/dev/urandom` rather than `/dev/random`.
 /// For more information see the linked man pages in lib.rs.
@@ -44,11 +45,10 @@ fn get_rng_fd() -> Result<libc::c_int, Error> {
 
     #[cold]
     fn get_fd_locked() -> Result<libc::c_int, Error> {
-        // SAFETY: We use the mutex only in this method, and we always unlock it
-        // before returning, making sure we don't violate the pthread_mutex_t API.
-        static MUTEX: Mutex = Mutex::new();
-        unsafe { MUTEX.lock() };
-        let _guard = DropGuard(|| unsafe { MUTEX.unlock() });
+        static MUTEX: Mutex<()> = Mutex::new(());
+        let _guard = MUTEX
+            .lock()
+            .map_err(|_: PoisonError<_>| Error::UNEXPECTED_FILE_MUTEX_POISONED)?;
 
         if let Some(fd) = get_fd() {
             return Ok(fd);
@@ -129,24 +129,6 @@ fn wait_until_rng_ready() -> Result<(), Error> {
     }
 }
 
-struct Mutex(UnsafeCell<libc::pthread_mutex_t>);
-
-impl Mutex {
-    const fn new() -> Self {
-        Self(UnsafeCell::new(libc::PTHREAD_MUTEX_INITIALIZER))
-    }
-    unsafe fn lock(&self) {
-        let r = libc::pthread_mutex_lock(self.0.get());
-        debug_assert_eq!(r, 0);
-    }
-    unsafe fn unlock(&self) {
-        let r = libc::pthread_mutex_unlock(self.0.get());
-        debug_assert_eq!(r, 0);
-    }
-}
-
-unsafe impl Sync for Mutex {}
-
 struct DropGuard<F: FnMut()>(F);
 
 impl<F: FnMut()> Drop for DropGuard<F> {