diff --git a/src/arch/common.rs b/src/arch/common.rs
new file mode 100644
index 0000000..8710a3e
--- /dev/null
+++ b/src/arch/common.rs
@@ -0,0 +1,31 @@
+// Copyright (c) 2015, edef <edef@edef.eu>
+// See the LICENSE file included in this distribution.
+use core::prelude::*;
+use core::mem::{size_of, align_of};
+use core::cmp::max;
+use core::ptr;
+
+use super::STACK_ALIGN;
+
+pub unsafe extern "C" fn rust_trampoline<F: FnOnce()>(f: *const F) {
+  ptr::read(f)()
+}
+
+pub unsafe fn push<T>(spp: &mut *mut usize, value: T) -> *mut T {
+  let mut sp = *spp as *mut T;
+  sp = offset_mut(sp, -1);
+  sp = align_down_mut(sp, max(align_of::<T>(), STACK_ALIGN));
+  *sp = value;
+  *spp = sp as *mut usize;
+  sp
+}
+
+pub fn align_down_mut<T>(sp: *mut T, n: usize) -> *mut T {
+  let sp = (sp as usize) & !(n - 1);
+  sp as *mut T
+}
+
+// ptr::offset_mut is positive ints only
+pub fn offset_mut<T>(ptr: *mut T, count: isize) -> *mut T {
+  (ptr as isize + count * (size_of::<T>() as isize)) as *mut T
+}
diff --git a/src/arch/mod.rs b/src/arch/mod.rs
index 1e5b3c6..128c7a3 100644
--- a/src/arch/mod.rs
+++ b/src/arch/mod.rs
@@ -1,6 +1,8 @@
 // Copyright (c) 2015, edef <edef@edef.eu>
 // See the LICENSE file included in this distribution.
-pub use self::imp::Registers;
+pub use self::imp::{Registers, STACK_ALIGN};
+
+mod common;
 
 #[cfg(target_arch = "x86_64")]
 #[path = "x86_64/mod.rs"]
diff --git a/src/arch/x86_64/mod.rs b/src/arch/x86_64/mod.rs
index 301e050..3f1b7a7 100644
--- a/src/arch/x86_64/mod.rs
+++ b/src/arch/x86_64/mod.rs
@@ -1,11 +1,11 @@
 // Copyright (c) 2015, edef <edef@edef.eu>
 // See the LICENSE file included in this distribution.
 use core::prelude::*;
-use core::mem::{size_of, align_of};
-use core::cmp::max;
-use core::ptr;
 
 use stack::Stack;
+use super::common::{push, rust_trampoline};
+
+pub const STACK_ALIGN: usize = 16;
 
 #[allow(raw_pointer_derive)]
 #[derive(Copy, Clone)]
@@ -47,26 +47,3 @@ impl Registers {
           : "volatile");
   }
 }
-
-unsafe extern "C" fn rust_trampoline<F: FnOnce()>(f: *const F) {
-  ptr::read(f)()
-}
-
-unsafe fn push<T>(spp: &mut *mut usize, value: T) -> *mut T {
-  let mut sp = *spp as *mut T;
-  sp = offset_mut(sp, -1);
-  sp = align_down_mut(sp, max(align_of::<T>(), 16));
-  *sp = value;
-  *spp = sp as *mut usize;
-  sp
-}
-
-fn align_down_mut<T>(sp: *mut T, n: usize) -> *mut T {
-  let sp = (sp as usize) & !(n - 1);
-  sp as *mut T
-}
-
-// ptr::offset_mut is positive ints only
-pub fn offset_mut<T>(ptr: *mut T, count: isize) -> *mut T {
-  (ptr as isize + count * (size_of::<T>() as isize)) as *mut T
-}