diff --git a/repos/base-hw/src/core/include/spec/x86_64/idt.h b/repos/base-hw/src/core/include/spec/x86_64/idt.h
index 004122f96..3980502fc 100644
--- a/repos/base-hw/src/core/include/spec/x86_64/idt.h
+++ b/repos/base-hw/src/core/include/spec/x86_64/idt.h
@@ -21,14 +21,6 @@ class Genode::Idt
 			SYSCALL_VEC = 0x80,
 		};
 
-		/**
-		 * Return virtual mtc address of the given label for the specified
-		 * virtual mode transition base.
-		 *
-		 * \param virt_base  virtual address of the mode transition pages
-		 */
-		static addr_t _virt_mtc_addr(addr_t const virt_base, addr_t const label);
-
 		/**
 		 * 64-Bit Mode IDT gate, see Intel SDM Vol. 3A, section 6.14.1.
 		 */
diff --git a/repos/base-hw/src/core/include/spec/x86_64/mtc_util.h b/repos/base-hw/src/core/include/spec/x86_64/mtc_util.h
new file mode 100644
index 000000000..64a30d8d4
--- /dev/null
+++ b/repos/base-hw/src/core/include/spec/x86_64/mtc_util.h
@@ -0,0 +1,23 @@
+#ifndef _MTC_UTIL_H_
+#define _MTC_UTIL_H_
+
+#include <base/stdint.h>
+
+extern int _mt_begin;
+
+namespace Genode
+{
+	/**
+	 * Return virtual mtc address of the given label for the specified
+	 * virtual mode transition base.
+	 *
+	 * \param virt_base  virtual base of the mode transition pages
+	 */
+	static addr_t _virt_mtc_addr(addr_t const virt_base, addr_t const label)
+	{
+		addr_t const phys_base = (addr_t)&_mt_begin;
+		return virt_base + (label - phys_base);
+	}
+}
+
+#endif /* _MTC_UTIL_H_ */
diff --git a/repos/base-hw/src/core/spec/x86_64/idt.cc b/repos/base-hw/src/core/spec/x86_64/idt.cc
index 10755c7da..30d666e17 100644
--- a/repos/base-hw/src/core/spec/x86_64/idt.cc
+++ b/repos/base-hw/src/core/spec/x86_64/idt.cc
@@ -1,19 +1,13 @@
 #include <pseudo_descriptor.h>
+#include <mtc_util.h>
 
 #include "idt.h"
 
-extern int _mt_begin;
 extern int _mt_idt;
 
 using namespace Genode;
 
 
-addr_t Idt::_virt_mtc_addr(addr_t const virt_base, addr_t const label)
-{
-	addr_t const phys_base = (addr_t)&_mt_begin;
-	return virt_base + (label - phys_base);
-}
-
 void Idt::setup()
 {
 	/* TODO: Calculate from _mt_isrs label */