diff --git a/src/platform/macos-x86_64/mod.rs b/src/platform/macos-x86_64/mod.rs
index e12e0d5..5241d81 100644
--- a/src/platform/macos-x86_64/mod.rs
+++ b/src/platform/macos-x86_64/mod.rs
@@ -11,11 +11,19 @@
 
 pub mod nr;
 
+/// Add the unix syscall class to the syscall number
+///
+/// https://opensource.apple.com/source/xnu/xnu-4570.41.2/osfmk/mach/i386/syscall_sw.h.auto.html
+#[inline(always)]
+pub fn syscall_construct_unix(n: usize) -> usize {
+    (2usize << 24) | (n & !(0xFFusize << 24))
+}
+
 #[inline(always)]
 pub unsafe fn syscall0(n: usize) -> usize {
     let ret: usize;
     asm!("syscall" : "={rax}"(ret)
-                   : "{rax}"(n)
+                   : "{rax}"(syscall_construct_unix(n))
                    : "rcx", "r11", "memory"
                    : "volatile");
     ret
@@ -25,7 +33,7 @@ pub unsafe fn syscall0(n: usize) -> usize {
 pub unsafe fn syscall1(n: usize, a1: usize) -> usize {
     let ret: usize;
     asm!("syscall" : "={rax}"(ret)
-                   : "{rax}"(n), "{rdi}"(a1)
+                   : "{rax}"(syscall_construct_unix(n)), "{rdi}"(a1)
                    : "rcx", "r11", "memory"
                    : "volatile");
     ret
@@ -35,7 +43,7 @@ pub unsafe fn syscall1(n: usize, a1: usize) -> usize {
 pub unsafe fn syscall2(n: usize, a1: usize, a2: usize) -> usize {
     let ret: usize;
     asm!("syscall" : "={rax}"(ret)
-                   : "{rax}"(n), "{rdi}"(a1), "{rsi}"(a2)
+                   : "{rax}"(syscall_construct_unix(n)), "{rdi}"(a1), "{rsi}"(a2)
                    : "rcx", "r11", "memory"
                    : "volatile");
     ret
@@ -45,7 +53,7 @@ pub unsafe fn syscall2(n: usize, a1: usize, a2: usize) -> usize {
 pub unsafe fn syscall3(n: usize, a1: usize, a2: usize, a3: usize) -> usize {
     let ret: usize;
     asm!("syscall" : "={rax}"(ret)
-                   : "{rax}"(n), "{rdi}"(a1), "{rsi}"(a2), "{rdx}"(a3)
+                   : "{rax}"(syscall_construct_unix(n)), "{rdi}"(a1), "{rsi}"(a2), "{rdx}"(a3)
                    : "rcx", "r11", "memory"
                    : "volatile");
     ret
@@ -60,7 +68,7 @@ pub unsafe fn syscall4(n: usize,
                        -> usize {
     let ret: usize;
     asm!("syscall" : "={rax}"(ret)
-                   : "{rax}"(n), "{rdi}"(a1), "{rsi}"(a2), "{rdx}"(a3),
+                   : "{rax}"(syscall_construct_unix(n)), "{rdi}"(a1), "{rsi}"(a2), "{rdx}"(a3),
                      "{r10}"(a4)
                    : "rcx", "r11", "memory"
                    : "volatile");
@@ -77,7 +85,7 @@ pub unsafe fn syscall5(n: usize,
                        -> usize {
     let ret: usize;
     asm!("syscall" : "={rax}"(ret)
-                   : "{rax}"(n), "{rdi}"(a1), "{rsi}"(a2), "{rdx}"(a3),
+                   : "{rax}"(syscall_construct_unix(n)), "{rdi}"(a1), "{rsi}"(a2), "{rdx}"(a3),
                      "{r10}"(a4), "{r8}"(a5)
                    : "rcx", "r11", "memory"
                    : "volatile");
@@ -95,7 +103,7 @@ pub unsafe fn syscall6(n: usize,
                        -> usize {
     let ret: usize;
     asm!("syscall" : "={rax}"(ret)
-                   : "{rax}"(n), "{rdi}"(a1), "{rsi}"(a2), "{rdx}"(a3),
+                   : "{rax}"(syscall_construct_unix(n)), "{rdi}"(a1), "{rsi}"(a2), "{rdx}"(a3),
                      "{r10}"(a4), "{r8}"(a5), "{r9}"(a6)
                    : "rcx", "r11", "memory"
                    : "volatile");