diff --git a/include/kernaux/arch/x86_64.h b/include/kernaux/arch/x86_64.h
index 73afd64..7127d4e 100644
--- a/include/kernaux/arch/x86_64.h
+++ b/include/kernaux/arch/x86_64.h
@@ -5,6 +5,8 @@
 extern "C" {
 #endif
 
+#include <stdint.h>
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/include/kernaux/asm/x86_64.h b/include/kernaux/asm/x86_64.h
index 6f71e0c..fcf3564 100644
--- a/include/kernaux/asm/x86_64.h
+++ b/include/kernaux/asm/x86_64.h
@@ -9,6 +9,64 @@ extern "C" {
 
 void kernaux_asm_x86_64_hang() __attribute__((noreturn));
 
+inline static uint8_t  kernaux_asm_x86_64_inportb(uint16_t port);
+inline static uint16_t kernaux_asm_x86_64_inportw(uint16_t port);
+inline static uint32_t kernaux_asm_x86_64_inportd(uint16_t port);
+inline static uint64_t kernaux_asm_x86_64_inportq(uint16_t port);
+
+inline static void kernaux_asm_x86_64_outportb(uint16_t port, uint8_t  value);
+inline static void kernaux_asm_x86_64_outportw(uint16_t port, uint16_t value);
+inline static void kernaux_asm_x86_64_outportd(uint16_t port, uint32_t value);
+inline static void kernaux_asm_x86_64_outportq(uint16_t port, uint64_t value);
+
+uint8_t kernaux_asm_x86_64_inportb(const uint16_t port)
+{
+    register uint8_t result;
+    __asm__ volatile("inb %1, %0" : "=a" (result) : "dN" (port));
+    return result;
+}
+
+uint16_t kernaux_asm_x86_64_inportw(const uint16_t port)
+{
+    register uint16_t result;
+    __asm__ volatile("inw %1, %0" : "=a" (result) : "dN" (port));
+    return result;
+}
+
+uint32_t kernaux_asm_x86_64_inportd(const uint16_t port)
+{
+    register uint32_t result;
+    __asm__ volatile("ind %1, %0" : "=a" (result) : "dN" (port));
+    return result;
+}
+
+uint64_t kernaux_asm_x86_64_inportq(const uint16_t port)
+{
+    register uint64_t result;
+    __asm__ volatile("inq %1, %0" : "=a" (result) : "dN" (port));
+    return result;
+}
+
+void kernaux_asm_x86_64_outportb(const uint16_t port, const uint8_t value)
+{
+    __asm__ volatile("outb %1, %0" : : "dN" (port), "a" (value));
+}
+
+void kernaux_asm_x86_64_outportw(const uint16_t port, const uint16_t value)
+{
+    __asm__ volatile("outw %1, %0" : : "dN" (port), "a" (value));
+}
+
+void kernaux_asm_x86_64_outportd(const uint16_t port, const uint32_t value)
+{
+    __asm__ volatile("outd %1, %0" : : "dN" (port), "a" (value));
+}
+
+void kernaux_asm_x86_64_outportq(const uint16_t port, const uint64_t value)
+{
+    __asm__ volatile("outq %1, %0" : : "dN" (port), "a" (value));
+}
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/src/console.c b/src/console.c
index cff793b..85dc606 100644
--- a/src/console.c
+++ b/src/console.c
@@ -5,6 +5,9 @@
 #ifdef ASM_I386
 #include <kernaux/asm/i386.h>
 #endif
+#ifdef ASM_X86_64
+#include <kernaux/asm/x86_64.h>
+#endif
 
 #include <kernaux/console.h>
 #include <kernaux/libc.h>
@@ -15,6 +18,9 @@ void kernaux_console_putc(const char c __attribute__((unused)))
 #ifdef ASM_I386
     kernaux_asm_i386_outportb(0x3F8, c);
 #endif
+#ifdef ASM_X86_64
+    kernaux_asm_x86_64_outportb(0x3F8, c);
+#endif
 }
 
 void kernaux_console_print(const char *const s)