diff --git a/xtoskrnl/includes/kd/dbgio.hh b/xtoskrnl/includes/kd/dbgio.hh
index 86aeaf8..fc04162 100644
--- a/xtoskrnl/includes/kd/dbgio.hh
+++ b/xtoskrnl/includes/kd/dbgio.hh
@@ -21,6 +21,7 @@ namespace KD
             STATIC PKD_PRINT_ROUTINE KdPrint;
 
         private:
+            STATIC KSPIN_LOCK DebugIoLock;
             STATIC KD_DEBUG_MODE DebugMode;
             STATIC PKD_INIT_ROUTINE IoProvidersInitRoutines[KDBG_PROVIDERS_COUNT];
             STATIC LIST_ENTRY Providers;
@@ -30,8 +31,8 @@ namespace KD
         public:
             STATIC XTCDECL VOID DbgPrint(PCWSTR Format,
                                          ...);
-            STATIC XTCDECL VOID DbgPrintEx(PCWSTR Format,
-                                           VA_LIST Arguments);
+            STATIC XTCDECL VOID DbgPrint(PCWSTR Format,
+                                         VA_LIST Arguments);
             STATIC XTAPI XTSTATUS InitializeDebugIoProviders(VOID);
             STATIC XTAPI VOID SetPrintRoutine(PKD_PRINT_ROUTINE DebugPrintRoutine);
 
diff --git a/xtoskrnl/kd/data.cc b/xtoskrnl/kd/data.cc
index acaaa9c..4a999a3 100644
--- a/xtoskrnl/kd/data.cc
+++ b/xtoskrnl/kd/data.cc
@@ -9,6 +9,9 @@
 #include <xtos.hh>
 
 
+/* Debug I/O spinlock */
+KSPIN_LOCK KD::DebugIo::DebugIoLock;
+
 /* Kernel Debugger mode */
 KD_DEBUG_MODE KD::DebugIo::DebugMode;
 
diff --git a/xtoskrnl/kd/dbgio.cc b/xtoskrnl/kd/dbgio.cc
index febf449..9e0925b 100644
--- a/xtoskrnl/kd/dbgio.cc
+++ b/xtoskrnl/kd/dbgio.cc
@@ -33,7 +33,7 @@ KD::DebugIo::DbgPrint(PCWSTR Format,
     VA_START(Arguments, Format);
 
     /* Call the actual debug print routine */
-    DbgPrintEx(Format, Arguments);
+    DbgPrint(Format, Arguments);
 
     /* Clean up the va_list */
     VA_END(Arguments);
@@ -54,12 +54,16 @@ KD::DebugIo::DbgPrint(PCWSTR Format,
  */
 XTCDECL
 VOID
-KD::DebugIo::DbgPrintEx(PCWSTR Format,
-                        VA_LIST Arguments)
+KD::DebugIo::DbgPrint(PCWSTR Format,
+                      VA_LIST Arguments)
 {
     PLIST_ENTRY DispatchTableEntry;
     PKD_DISPATCH_TABLE DispatchTable;
 
+    /* Raise runlevel and acquire the Debug I/O lock */
+    KE::RaiseRunLevel RunLevel(HIGH_LEVEL);
+    KE::SpinLockGuard SpinLock(&DebugIoLock);
+
     /* Iterate over all registered debug providers */
     DispatchTableEntry = Providers.Flink;
     while(DispatchTableEntry != &Providers)
@@ -218,6 +222,9 @@ KD::DebugIo::InitializeDebugIoProviders(VOID)
     ULONG Index;
     XTSTATUS ProviderStatus, Status;
 
+    /* Initialize debug I/O spinlock */
+    KE::SpinLock::InitializeSpinLock(&DebugIoLock);
+
     /* Initialize debug providers list */
     RTL::LinkedList::InitializeListHead(&Providers);
 
diff --git a/xtoskrnl/kd/exports.cc b/xtoskrnl/kd/exports.cc
index 622fade..06c727a 100644
--- a/xtoskrnl/kd/exports.cc
+++ b/xtoskrnl/kd/exports.cc
@@ -33,7 +33,7 @@ DbgPrint(PCWSTR Format,
     /* Initialise the va_list */
     VA_START(Arguments, Format);
 
-    KD::DebugIo::DbgPrintEx(Format, Arguments);
+    KD::DebugIo::DbgPrint(Format, Arguments);
 
     /* Clean up the va_list */
     VA_END(Arguments);