diff --git a/src/tools/miri/src/shims/unix/linux/fd.rs b/src/tools/miri/src/shims/unix/linux/fd.rs
index 3c4a678e598d..3c263e4df928 100644
--- a/src/tools/miri/src/shims/unix/linux/fd.rs
+++ b/src/tools/miri/src/shims/unix/linux/fd.rs
@@ -152,7 +152,6 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
         let _maxevents = this.read_scalar(maxevents)?.to_i32()?;
         let _timeout = this.read_scalar(timeout)?.to_i32()?;
 
-        let numevents = 0;
         if let Some(epfd) = this.machine.file_handler.handles.get_mut(&epfd) {
             let _epfd = epfd
                 .as_any_mut()
@@ -160,7 +159,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                 .ok_or_else(|| err_unsup_format!("non-epoll FD passed to `epoll_wait`"))?;
 
             // FIXME return number of events ready when scheme for marking events ready exists
-            Ok(Scalar::from_i32(numevents))
+            throw_unsup_format!("returning ready events from epoll_wait is not yet implemented");
         } else {
             Ok(Scalar::from_i32(this.handle_not_found()?))
         }
diff --git a/src/tools/miri/tests/pass-dep/tokio/sleep.rs b/src/tools/miri/tests/fail/tokio/sleep.rs
similarity index 76%
rename from src/tools/miri/tests/pass-dep/tokio/sleep.rs
rename to src/tools/miri/tests/fail/tokio/sleep.rs
index 00cc68eba3ea..6fdfbc9913a1 100644
--- a/src/tools/miri/tests/pass-dep/tokio/sleep.rs
+++ b/src/tools/miri/tests/fail/tokio/sleep.rs
@@ -1,5 +1,7 @@
 //@compile-flags: -Zmiri-permissive-provenance -Zmiri-backtrace=full
 //@only-target-x86_64-unknown-linux: support for tokio only on linux and x86
+//@error-pattern: returning ready events from epoll_wait is not yet implemented
+//@normalize-stderr-test: " += note:.*\n" -> ""
 
 use tokio::time::{sleep, Duration, Instant};
 
diff --git a/src/tools/miri/tests/fail/tokio/sleep.stderr b/src/tools/miri/tests/fail/tokio/sleep.stderr
new file mode 100644
index 000000000000..ac2a984ed514
--- /dev/null
+++ b/src/tools/miri/tests/fail/tokio/sleep.stderr
@@ -0,0 +1,15 @@
+error: unsupported operation: returning ready events from epoll_wait is not yet implemented
+  --> CARGO_REGISTRY/.../epoll.rs:LL:CC
+   |
+LL | /         syscall!(epoll_wait(
+LL | |             self.ep,
+LL | |             events.as_mut_ptr(),
+LL | |             events.capacity() as i32,
+LL | |             timeout,
+LL | |         ))
+   | |__________^ returning ready events from epoll_wait is not yet implemented
+   |
+   = help: this is likely not a bug in the program; it indicates that the program performed an operation that the interpreter does not support
+
+error: aborting due to previous error
+