diff --git a/arch/x86_64/percpu.c b/arch/x86_64/percpu.c
index 8994957..ec2848b 100644
--- a/arch/x86_64/percpu.c
+++ b/arch/x86_64/percpu.c
@@ -84,7 +84,7 @@ void x86_64_cpu_setup(struct percpu* cpu) {
 
     // Enable SSE.
     cr0 &= ~CR0_EM;
-    cr0 |= CR0_MP;
+    cr0 |= CR0_MP | CR0_WP;
     cr4 |= CR4_OSFXSR | CR4_OSXMMEXCPT;
 
     if (cpuid1.ecx & CPUID_1C_XSAVE) {