diff --git a/changelog/2747.changed.md b/changelog/2747.changed.md
new file mode 100644
index 0000000000..bfce6b898c
--- /dev/null
+++ b/changelog/2747.changed.md
@@ -0,0 +1 @@
+`Dir::as_raw_fd` now panics if `libc::dirfd` returns a negative value.
diff --git a/src/dir.rs b/src/dir.rs
index 80bf1b56c9..f90824dbc9 100644
--- a/src/dir.rs
+++ b/src/dir.rs
@@ -137,7 +137,9 @@ impl std::os::fd::AsFd for Dir {
 
 impl AsRawFd for Dir {
     fn as_raw_fd(&self) -> RawFd {
-        unsafe { libc::dirfd(self.0.as_ptr()) }
+        let fd = unsafe { libc::dirfd(self.0.as_ptr()) };
+        assert!(fd >= 0, "dirfd returned error: {}", Errno::last());
+        fd
     }
 }