diff --git a/Architecture/amd64/cpu/AdvancedProgrammableInterruptController.cpp b/Architecture/amd64/cpu/AdvancedProgrammableInterruptController.cpp
index 28f2f16..c454d1c 100644
--- a/Architecture/amd64/cpu/AdvancedProgrammableInterruptController.cpp
+++ b/Architecture/amd64/cpu/AdvancedProgrammableInterruptController.cpp
@@ -49,7 +49,8 @@ namespace APIC
 
     void APIC::Write(uint32_t Register, uint32_t Value)
     {
-        debug("APIC::Write(%#lx, %#lx)", Register, Value);
+        if (Register != APIC_EOI)
+            debug("APIC::Write(%#lx, %#lx)", Register, Value);
         if (x2APICSupported)
         {
             if (Register != APIC_ICRHI)
@@ -216,7 +217,7 @@ namespace APIC
 
     void Timer::OnInterruptReceived(CPU::x64::TrapFrame *Frame)
     {
-        fixme("APIC IRQ0 INTERRUPT RECEIVED ON CPU %d", CPU::x64::rdmsr(CPU::x64::MSR_FS_BASE));
+        // fixme("APIC IRQ0 INTERRUPT RECEIVED ON CPU %d", CPU::x64::rdmsr(CPU::x64::MSR_FS_BASE));
     }
 
     Timer::Timer(APIC *apic) : Interrupts::Handler(CPU::x64::IRQ0)
diff --git a/Architecture/amd64/cpu/SymmetricMultiprocessing.cpp b/Architecture/amd64/cpu/SymmetricMultiprocessing.cpp
index e14e48c..d06684f 100644
--- a/Architecture/amd64/cpu/SymmetricMultiprocessing.cpp
+++ b/Architecture/amd64/cpu/SymmetricMultiprocessing.cpp
@@ -72,7 +72,7 @@ extern "C" void StartCPU()
     CPU::Interrupts(CPU::Enable);
     KPrint("CPU %d is online", CPU_ID);
     CPUEnabled = true;
-    CPU::Stop();
+    CPU::Stop(); // Stop and surpress interrupts.
 }
 
 namespace SMP
diff --git a/Core/Debugger.cpp b/Core/Debugger.cpp
index 34d14d6..ae128fc 100644
--- a/Core/Debugger.cpp
+++ b/Core/Debugger.cpp
@@ -2,6 +2,9 @@
 
 #include <uart.hpp>
 #include <printf.h>
+#include <lock.hpp>
+
+NEWLOCK(DebuggerLock);
 
 using namespace UniversalAsynchronousReceiverTransmitter;
 
@@ -54,6 +57,7 @@ namespace SysDbg
 
     void WriteLine(DebugLevel Level, const char *File, int Line, const char *Function, const char *Format, ...)
     {
+        SMARTLOCK(DebuggerLock);
         WritePrefix(Level, File, Line, Function);
         va_list args;
         va_start(args, Format);