diff --git a/src/helpers.rs b/src/helpers.rs
index 7d68d05cdb7..616de837879 100644
--- a/src/helpers.rs
+++ b/src/helpers.rs
@@ -360,8 +360,8 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
         this.read_scalar(errno_place.into())?.not_undef()
     }
 
-    /// Sets the last error variable using a `std::io::Error`. It fails if the error cannot be
-    /// transformed to a raw os error succesfully.
+    /// Sets the last OS error using a `std::io::Error`. This function tries to produce the most
+    /// similar OS error from the `std::io::ErrorKind` and sets it as the last OS error.
     fn set_last_error_from_io_error(&mut self, e: std::io::Error) -> InterpResult<'tcx> {
         use std::io::ErrorKind::*;
         let this = self.eval_context_mut();
@@ -392,12 +392,12 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
     }
 
     /// Helper function that consumes an `std::io::Result<T>` and returns an
-    /// `InterpResult<'tcx,T>::Ok` instead. It is expected that the result can be converted to an
-    /// OS error using `std::io::Error::raw_os_error`.
+    /// `InterpResult<'tcx,T>::Ok` instead. In case the result is an error, this function returns
+    /// `Ok(-1)` and sets the last OS error accordingly.
     ///
     /// This function uses `T: From<i32>` instead of `i32` directly because some IO related
     /// functions return different integer types (like `read`, that returns an `i64`)
-    fn set_last_error_from_io_result<T: From<i32>>(
+    fn try_unwrap_io_result<T: From<i32>>(
         &mut self,
         result: std::io::Result<T>,
     ) -> InterpResult<'tcx, T> {
diff --git a/src/machine.rs b/src/machine.rs
index 3714aa2d799..315e9c1a35a 100644
--- a/src/machine.rs
+++ b/src/machine.rs
@@ -91,7 +91,7 @@ pub struct Evaluator<'tcx> {
     pub(crate) argv: Option<Pointer<Tag>>,
     pub(crate) cmd_line: Option<Pointer<Tag>>,
 
-    /// Last OS error location in memory. It is a 32 bits integer (unsigned for Windows)
+    /// Last OS error location in memory. It is a 32 bit integer (unsigned for Windows)
     pub(crate) last_error: Option<MPlaceTy<'tcx, Tag>>,
 
     /// TLS state.
diff --git a/src/shims/fs.rs b/src/shims/fs.rs
index c8d1eb29562..ffcfab10081 100644
--- a/src/shims/fs.rs
+++ b/src/shims/fs.rs
@@ -108,7 +108,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
             fh.low
         });
 
-        this.set_last_error_from_io_result(fd)
+        this.try_unwrap_io_result(fd)
     }
 
     fn fcntl(
@@ -144,7 +144,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
         let fd = this.read_scalar(fd_op)?.to_i32()?;
 
         this.remove_handle_and(fd, |handle, this| {
-            this.set_last_error_from_io_result(handle.file.sync_all().map(|_| 0i32))
+            this.try_unwrap_io_result(handle.file.sync_all().map(|_| 0i32))
         })
     }
 
@@ -175,9 +175,8 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
                     .get_bytes_mut(&*this.tcx, buf, Size::from_bytes(count))
                     .map(|buffer| handle.file.read(buffer))
             });
-            // Reinsert the file handle
             this.machine.file_handler.handles.insert(fd, handle).unwrap_none();
-            this.set_last_error_from_io_result(bytes?.map(|bytes| bytes as i64))
+            this.try_unwrap_io_result(bytes?.map(|bytes| bytes as i64))
         })
     }
 
@@ -206,7 +205,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
                     .map(|bytes| handle.file.write(bytes).map(|bytes| bytes as i64))
             });
             this.machine.file_handler.handles.insert(fd, handle).unwrap_none();
-            this.set_last_error_from_io_result(bytes?)
+            this.try_unwrap_io_result(bytes?)
         })
     }
 
@@ -223,7 +222,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
 
         let result = remove_file(path).map(|_| 0);
 
-        this.set_last_error_from_io_result(result)
+        this.try_unwrap_io_result(result)
     }
 
     /// Helper function that gets a `FileHandle` immutable reference and allows to manipulate it