diff --git a/src/scheme/acpi.rs b/src/scheme/acpi.rs
index 1ee3739..9fe6020 100644
--- a/src/scheme/acpi.rs
+++ b/src/scheme/acpi.rs
@@ -9,7 +9,7 @@ use alloc::vec::Vec;
 use syscall::data::Stat;
 use syscall::error::{EACCES, EBADF, EBADFD, EINVAL, EIO, EISDIR, ENOENT, ENOTDIR};
 use syscall::flag::{O_ACCMODE, O_DIRECTORY, O_RDWR, O_STAT, O_WRONLY};
-use syscall::scheme::Scheme;
+use syscall::scheme::{calc_seek_offset_usize, Scheme};
 use syscall::{Error, Result};
 use syscall::{MODE_DIR, MODE_FILE};
 
@@ -18,7 +18,6 @@ use spin::{Mutex, RwLock};
 use crate::acpi::sdt::Sdt;
 use crate::acpi::SdtSignature;
 use crate::paging::ActivePageTable;
-use crate::scheme::calc_seek_offset_usize;
 
 #[derive(Clone, Copy)]
 struct PhysSlice {
diff --git a/src/scheme/initfs.rs b/src/scheme/initfs.rs
index 17f3172..d5d6447 100644
--- a/src/scheme/initfs.rs
+++ b/src/scheme/initfs.rs
@@ -3,11 +3,10 @@ use core::str;
 use core::sync::atomic::{AtomicUsize, Ordering};
 use spin::RwLock;
 
-use crate::scheme::calc_seek_offset_usize;
 use crate::syscall::data::Stat;
 use crate::syscall::error::*;
 use crate::syscall::flag::{MODE_DIR, MODE_FILE};
-use crate::syscall::scheme::Scheme;
+use crate::syscall::scheme::{calc_seek_offset_usize, Scheme};
 
 #[cfg(test)]
 mod gen {
diff --git a/src/scheme/irq.rs b/src/scheme/irq.rs
index 3400eda..d5938d0 100644
--- a/src/scheme/irq.rs
+++ b/src/scheme/irq.rs
@@ -12,10 +12,10 @@ use crate::arch::interrupt::{available_irqs_iter, bsp_apic_id, is_reserved, set_
 
 use crate::event;
 use crate::interrupt::irq::acknowledge;
-use crate::scheme::{AtomicSchemeId, SchemeId, calc_seek_offset_usize};
+use crate::scheme::{AtomicSchemeId, SchemeId};
 use crate::syscall::error::*;
 use crate::syscall::flag::{EventFlags, EVENT_READ, O_DIRECTORY, O_CREAT, O_STAT, MODE_CHR, MODE_DIR};
-use crate::syscall::scheme::Scheme;
+use crate::syscall::scheme::{calc_seek_offset_usize, Scheme};
 
 pub static IRQ_SCHEME_ID: AtomicSchemeId = AtomicSchemeId::default();
 
diff --git a/src/scheme/mod.rs b/src/scheme/mod.rs
index cf0a028..d337a08 100644
--- a/src/scheme/mod.rs
+++ b/src/scheme/mod.rs
@@ -10,14 +10,11 @@ use alloc::sync::Arc;
 use alloc::boxed::Box;
 use alloc::collections::BTreeMap;
 use alloc::vec::Vec;
-use core::cmp;
 use core::sync::atomic::AtomicUsize;
-use core::convert::TryFrom;
 use spin::{Once, RwLock, RwLockReadGuard, RwLockWriteGuard};
 
 use crate::syscall::error::*;
 use crate::syscall::scheme::Scheme;
-use crate::syscall::flag::{SEEK_CUR, SEEK_END, SEEK_SET};
 
 #[cfg(feature = "acpi")]
 use self::acpi::AcpiScheme;
@@ -286,32 +283,3 @@ pub fn schemes() -> RwLockReadGuard<'static, SchemeList> {
 pub fn schemes_mut() -> RwLockWriteGuard<'static, SchemeList> {
     SCHEMES.call_once(init_schemes).write()
 }
-
-/// Helper for seek calls
-/// In most cases it's easier to use a usize to track the offset and buffer size internally,
-/// but the seek interface uses isize.  This wrapper ensures EOVERFLOW errors are returned
-/// as appropriate if the value in the usize can't fit in the isize.
-pub fn calc_seek_offset_usize(cur_offset: usize, pos: isize, whence: usize, buf_len: usize) -> Result<isize> {
-    let cur_offset = isize::try_from(cur_offset).or_else(|_| Err(Error::new(EOVERFLOW)))?;
-    let buf_len = isize::try_from(buf_len).or_else(|_| Err(Error::new(EOVERFLOW)))?;
-    calc_seek_offset_isize(cur_offset, pos, whence, buf_len)
-}
-
-/// Helper for seek calls
-/// Result is guaranteed to be positive.
-/// EOVERFLOW returned if the arguments would cause an overflow.
-/// EINVAL returned if the new offset is out of bounds.
-pub fn calc_seek_offset_isize(cur_offset: isize, pos: isize, whence: usize, buf_len: isize) -> Result<isize> {
-    let new_offset = match whence {
-        SEEK_CUR => pos.checked_add(cur_offset),
-        SEEK_END => pos.checked_add(buf_len),
-        SEEK_SET => Some(pos),
-        _ => None,
-    };
-
-    match new_offset {
-        Some(new_offset) if new_offset < 0 => Err(Error::new(EINVAL)),
-        Some(new_offset) => Ok(cmp::min(new_offset, buf_len)),
-        None => Err(Error::new(EOVERFLOW))
-    }
-}
diff --git a/src/scheme/proc.rs b/src/scheme/proc.rs
index c792ec4..da27553 100644
--- a/src/scheme/proc.rs
+++ b/src/scheme/proc.rs
@@ -2,12 +2,12 @@ use crate::{
     arch::paging::VirtualAddress,
     context::{self, Context, ContextId, Status},
     ptrace,
-    scheme::{AtomicSchemeId, SchemeId, calc_seek_offset_usize},
+    scheme::{AtomicSchemeId, SchemeId},
     syscall::{
         data::{FloatRegisters, IntRegisters, PtraceEvent},
         error::*,
         flag::*,
-        scheme::Scheme,
+        scheme::{calc_seek_offset_usize, Scheme},
         self,
         validate,
     },
diff --git a/src/scheme/root.rs b/src/scheme/root.rs
index 078da96..ca5e789 100644
--- a/src/scheme/root.rs
+++ b/src/scheme/root.rs
@@ -9,9 +9,9 @@ use spin::{Mutex, RwLock};
 use crate::context;
 use crate::syscall::data::Stat;
 use crate::syscall::error::*;
-use crate::syscall::flag::{EventFlags, O_CREAT, MODE_FILE, MODE_DIR, SEEK_SET, SEEK_CUR, SEEK_END};
-use crate::syscall::scheme::Scheme;
-use crate::scheme::{self, SchemeNamespace, SchemeId, calc_seek_offset_usize};
+use crate::syscall::flag::{EventFlags, O_CREAT, MODE_FILE, MODE_DIR};
+use crate::syscall::scheme::{calc_seek_offset_usize, Scheme};
+use crate::scheme::{self, SchemeNamespace, SchemeId};
 use crate::scheme::user::{UserInner, UserScheme};
 
 struct FolderInner {
diff --git a/src/scheme/sys/mod.rs b/src/scheme/sys/mod.rs
index e90b136..f0a03d0 100644
--- a/src/scheme/sys/mod.rs
+++ b/src/scheme/sys/mod.rs
@@ -5,11 +5,10 @@ use core::str;
 use core::sync::atomic::{AtomicUsize, Ordering};
 use spin::RwLock;
 
-use crate::scheme::calc_seek_offset_usize;
 use crate::syscall::data::Stat;
 use crate::syscall::error::{Error, EBADF, ENOENT, Result};
 use crate::syscall::flag::{MODE_DIR, MODE_FILE};
-use crate::syscall::scheme::Scheme;
+use crate::syscall::scheme::{calc_seek_offset_usize, Scheme};
 use crate::arch::interrupt::irq;
 
 mod block;