diff --git a/posts/2015-09-02-setup-rust.md b/posts/2015-09-02-setup-rust.md
index 0221944a..24cf25c4 100644
--- a/posts/2015-09-02-setup-rust.md
+++ b/posts/2015-09-02-setup-rust.md
@@ -273,41 +273,27 @@ Through `objdump -D` we disassemble our whole kernel and `grep` picks the releva
 The rough translation of this cryptic definition is: _If SSE isn't enabled_. So apparently Rust uses SSE instructions by default and we didn't enable SSE before. So the fix for this bug is enabling SSE.
 
 ### Enabling SSE
-To enable SSE, assembly code is needed again. We want to add a function that tests if SSE is available and enables it then. Else we want to print an error message. But we can't use our existing `error` procedure because it uses (now invalid) 32-bit instructions. So we need a new one (in `long_mode_init.asm`):
+To enable SSE, assembly code is needed again. We want to add a function that tests if SSE is available and enables it then. Else we want to print an error message.
 
-```nasm
-; Prints `ERROR: ` and the given error code to screen and hangs.
-; parameter: error code (in ascii) in al
-error:
-    mov rbx, 0x4f4f4f524f524f45
-    mov [0xb8000], rbx
-    mov rbx, 0x4f204f204f3a4f52
-    mov [0xb8008], rbx
-    mov byte [0xb800e], al
-    hlt
-    jmp error
-```
-It's the nearly the same as the 32-bit procedure in the [previous post][32-bit error function] (instead of `ERR:` we print `ERROR:` here).
-
-Now we can add a function that checks for SSE and enables it:
+We add it to the `boot.asm` file:
 
 ```nasm
 ; Check for SSE and enable it. If it's not supported throw error "a".
 setup_SSE:
     ; check for SSE
-    mov rax, 0x1
+    mov eax, 0x1
     cpuid
     test edx, 1<<25
     jz .no_SSE
 
     ; enable SSE
-    mov rax, cr0
+    mov eax, cr0
     and ax, 0xFFFB      ; clear coprocessor emulation CR0.EM
     or ax, 0x2          ; set coprocessor monitoring  CR0.MP
-    mov cr0, rax
-    mov rax, cr4
+    mov cr0, eax
+    mov eax, cr4
     or ax, 3 << 9       ; set CR4.OSFXSR and CR4.OSXMMEXCPT at the same time
-    mov cr4, rax
+    mov cr4, eax
 
     ret
 .no_SSE:
@@ -316,7 +302,7 @@ setup_SSE:
 ```
 The code is from the great [OSDev Wiki][osdev sse] again. Notice that it sets/unsets exactly the bits that can cause the `Invalid Opcode` exception.
 
-When we insert a `call setup_SSE` right before calling `rust_main`, our Rust code will finally work.
+When we insert a `call setup_SSE` somewhere in the `start` function (for example after `call enable_paging`), our Rust code will finally work.
 
 [32-bit error function]: {{ page.previous.url }}#some-tests
 [osdev sse]: http://wiki.osdev.org/SSE#Checking_for_SSE
diff --git a/src/arch/x86_64/boot.asm b/src/arch/x86_64/boot.asm
index 7035fc17..ade4dc4a 100644
--- a/src/arch/x86_64/boot.asm
+++ b/src/arch/x86_64/boot.asm
@@ -29,6 +29,7 @@ start:
 
     call setup_page_tables
     call enable_paging
+    call setup_SSE
 
     ; load the 64-bit GDT
     lgdt [gdt64.pointer]
@@ -147,6 +148,28 @@ test_long_mode:
     mov al, "2"
     jmp error
 
+; Check for SSE and enable it. If it's not supported throw error "a".
+setup_SSE:
+    ; check for SSE
+    mov eax, 0x1
+    cpuid
+    test edx, 1<<25
+    jz .no_SSE
+
+    ; enable SSE
+    mov eax, cr0
+    and ax, 0xFFFB      ; clear coprocessor emulation CR0.EM
+    or ax, 0x2          ; set coprocessor monitoring  CR0.MP
+    mov cr0, eax
+    mov eax, cr4
+    or ax, 3 << 9       ; set CR4.OSFXSR and CR4.OSXMMEXCPT at the same time
+    mov cr4, eax
+
+    ret
+.no_SSE:
+    mov al, "a"
+    jmp error
+
 section .bss
 align 4096
 p4_table:
diff --git a/src/arch/x86_64/long_mode_init.asm b/src/arch/x86_64/long_mode_init.asm
index 47927d58..bcf588a8 100644
--- a/src/arch/x86_64/long_mode_init.asm
+++ b/src/arch/x86_64/long_mode_init.asm
@@ -18,8 +18,6 @@ extern rust_main
 section .text
 bits 64
 long_mode_start:
-    call setup_SSE
-
     ; call rust main (with multiboot pointer in rdi)
     call rust_main
 .os_returned:
@@ -31,36 +29,3 @@ long_mode_start:
     mov rax, 0x4f214f644f654f6e
     mov [0xb8010], rax
     hlt
-
-; Check for SSE and enable it. If it's not supported throw error "a".
-setup_SSE:
-    ; check for SSE
-    mov rax, 0x1
-    cpuid
-    test edx, 1<<25
-    jz .no_SSE
-
-    ; enable SSE
-    mov rax, cr0
-    and ax, 0xFFFB      ; clear coprocessor emulation CR0.EM
-    or ax, 0x2          ; set coprocessor monitoring  CR0.MP
-    mov cr0, rax
-    mov rax, cr4
-    or ax, 3 << 9       ; set CR4.OSFXSR and CR4.OSXMMEXCPT at the same time
-    mov cr4, rax
-
-    ret
-.no_SSE:
-    mov al, "a"
-    jmp error
-
-; Prints `ERROR: ` and the given error code to screen and hangs.
-; parameter: error code (in ascii) in al
-error:
-    mov rbx, 0x4f4f4f524f524f45
-    mov [0xb8000], rbx
-    mov rbx, 0x4f204f204f3a4f52
-    mov [0xb8008], rbx
-    mov byte [0xb800e], al
-    hlt
-    jmp error