diff --git a/examples/typephp-os/README.md b/examples/typephp-os/README.md
index 26c2f37c..bc7e8871 100644
--- a/examples/typephp-os/README.md
+++ b/examples/typephp-os/README.md
@@ -224,13 +224,16 @@ segment.
 The native x86-64 `SYSCALL` boundary provides synchronous `read`, `write`, `close`,
 `lseek`, `openat`, `exit`/`exit_group`, `getcwd`, `chdir`, `mkdir`, `rmdir`,
 `unlink`, file stat/access/persistence/truncation families, fixed identity
-queries, `time`, `gettimeofday`, `clock_gettime`, `clock_getres`, `brk`,
+queries, `time`, `gettimeofday`, `clock_gettime`, `clock_getres`, `nanosleep`, `brk`,
 anonymous private `mmap`, `mprotect`, `munmap`, `getdents64`, the initial
 `fcntl` flag operations, fixed-console `ioctl(TIOCGWINSZ)`, and private
 spawn and same-directory rename operations. The former private directory-list
 syscall has been removed; `ls` and PHP Nano use the standard directory ABI. Standard
 input and output are backed by QEMU's COM1 serial console. Syscall numbers are
 shared by the kernel and userspace through `typephp_os_syscall.h`.
+The 8259 PIC routes a 100 Hz PIT timer on IRQ0 and COM1 input on IRQ4. Console
+reads and sleeps block with `HLT` until an interrupt arrives, so the resident
+shell no longer consumes a host CPU core while it waits at the prompt.
 Entry immediately switches from the untrusted user RSP to a dedicated kernel
 stack. Return uses `iretq`, allowing synchronous spawn/exit to replace the
 complete saved user context.
diff --git a/examples/typephp-os/ROADMAP.md b/examples/typephp-os/ROADMAP.md
index eb59011e..27b87dd2 100644
--- a/examples/typephp-os/ROADMAP.md
+++ b/examples/typephp-os/ROADMAP.md
@@ -98,14 +98,15 @@ behavior.
    does not yet replace the working userspace commands.
    Single-task identity calls report PID/TID 1 for the resident shell, 2 for
    its synchronous foreground command, and root UID/GID. Linux-compatible
-   wall/monotonic clock structures are exposed at the current one-second RTC
-   resolution. The `systest` ELF exercises this complete syscall slice.
+   wall-clock time uses the RTC while monotonic time and blocking sleeps use a
+   100 Hz PIT. The `systest` ELF exercises this complete syscall slice.
    Syscall evolution follows the glibc migration rules in `user/README.md`.
 7. **Native Class memory.** Exercise Wren GC through Zend MM and verify tracing
    of PHPX fields under sustained allocation.
-8. **Kernel services.** Interrupt-driven timer and keyboard, higher-level VM
-   region management, Zend-chunk reclamation, and a capability-oriented native
-   API.
+8. **Kernel services.** The legacy PIC, a 100 Hz PIT clock, interrupt-driven
+   COM1 input, blocking console reads, and blocking `nanosleep` are implemented.
+   Higher-level VM region management, Zend-chunk reclamation, and a
+   capability-oriented native API remain future work.
 9. **Packaging and CI.** Automate the two-stage ELF32/ELF64 build and QEMU boot
    smoke test in GitHub Actions.
 
diff --git a/examples/typephp-os/kernel/core/abi/typephp_os_abi.h b/examples/typephp-os/kernel/core/abi/typephp_os_abi.h
index 4e3737c6..821209d8 100644
--- a/examples/typephp-os/kernel/core/abi/typephp_os_abi.h
+++ b/examples/typephp-os/kernel/core/abi/typephp_os_abi.h
@@ -43,6 +43,8 @@ void typephp_os_process_start(void);
 long typephp_os_fs_path_type(const char *path);
 long typephp_os_fs_getdents64(int fd, void *buffer, size_t capacity);
 long typephp_os_console_read(void *buffer, size_t size);
+void typephp_os_console_enable_interrupts(void);
+void typephp_os_console_interrupt(void);
 
 #ifdef __cplusplus
 }
diff --git a/examples/typephp-os/kernel/core/abi/typephp_os_syscall.h b/examples/typephp-os/kernel/core/abi/typephp_os_syscall.h
index 91e3f512..56665f42 100644
--- a/examples/typephp-os/kernel/core/abi/typephp_os_syscall.h
+++ b/examples/typephp-os/kernel/core/abi/typephp_os_syscall.h
@@ -18,6 +18,7 @@ enum typephp_os_syscall_number {
     TYPEPHP_SYS_BRK = 12,
     TYPEPHP_SYS_IOCTL = 16,
     TYPEPHP_SYS_ACCESS = 21,
+    TYPEPHP_SYS_NANOSLEEP = 35,
     TYPEPHP_SYS_GETPID = 39,
     TYPEPHP_SYS_EXIT = 60,
     TYPEPHP_SYS_UNAME = 63,
diff --git a/examples/typephp-os/kernel/core/kernel.c b/examples/typephp-os/kernel/core/kernel.c
index 805609ca..8366e87d 100644
--- a/examples/typephp-os/kernel/core/kernel.c
+++ b/examples/typephp-os/kernel/core/kernel.c
@@ -8,11 +8,15 @@ enum {
     VGA_WIDTH = 80,
     VGA_HEIGHT = 25,
     COM1 = 0x3f8,
+    SERIAL_BUFFER_SIZE = 8192,
 };
 
 static volatile uint16_t *const vga = (volatile uint16_t *) 0xb8000;
 static uint32_t row;
 static uint32_t column;
+static volatile uint32_t serial_read_head;
+static volatile uint32_t serial_read_tail;
+static volatile uint8_t serial_read_buffer[SERIAL_BUFFER_SIZE];
 
 static inline void outb(uint16_t port, uint8_t value)
 {
@@ -37,6 +41,25 @@ static void serial_init(void)
     outb(COM1 + 4, 0x0b);
 }
 
+void typephp_os_console_enable_interrupts(void)
+{
+    /* Received-data-available interrupt. MCR.OUT2 was enabled by serial_init
+     * and routes the UART interrupt to the legacy PIC's IRQ4 input. */
+    outb(COM1 + 1, 0x01);
+}
+
+void typephp_os_console_interrupt(void)
+{
+    while ((inb(COM1 + 5) & 0x01u) != 0) {
+        const uint8_t value = inb(COM1);
+        const uint32_t next = (serial_read_head + 1u) % SERIAL_BUFFER_SIZE;
+        if (next != serial_read_tail) {
+            serial_read_buffer[serial_read_head] = value;
+            serial_read_head = next;
+        }
+    }
+}
+
 static void serial_put(uint8_t value)
 {
     while ((inb(COM1 + 5) & 0x20u) == 0) {
@@ -50,14 +73,18 @@ long typephp_os_console_read(void *buffer, unsigned long size)
     if (output == 0 || size == 0) {
         return 0;
     }
-    /* COM1 is the standard input device for the headless QEMU target. Keep
-     * this synchronous: the process model intentionally has one foreground
-     * task and no scheduler yet. */
-    while ((inb(COM1 + 5) & 0x01u) == 0) {
-        __asm__ volatile("pause");
+    /* The system remains single-task, but a blocking read can still halt the
+     * CPU until IRQ4 supplies input. STI followed immediately by HLT avoids
+     * the empty-buffer/check-to-sleep lost-wakeup race on x86. */
+    for (;;) {
+        __asm__ volatile("cli" : : : "memory");
+        if (serial_read_tail != serial_read_head) {
+            output[0] = serial_read_buffer[serial_read_tail];
+            serial_read_tail = (serial_read_tail + 1u) % SERIAL_BUFFER_SIZE;
+            return 1;
+        }
+        __asm__ volatile("sti; hlt; cli" : : : "memory");
     }
-    output[0] = inb(COM1);
-    return 1;
 }
 
 static void vga_scroll(void)
diff --git a/examples/typephp-os/kernel/core/process-entry.S b/examples/typephp-os/kernel/core/process-entry.S
index 9f1abd46..5003844a 100644
--- a/examples/typephp-os/kernel/core/process-entry.S
+++ b/examples/typephp-os/kernel/core/process-entry.S
@@ -89,6 +89,60 @@ TYPEPHP_EXCEPTION_WITH_ERROR 12
 TYPEPHP_EXCEPTION_WITH_ERROR 13
 TYPEPHP_EXCEPTION_WITH_ERROR 14
 
+.macro TYPEPHP_IRQ number vector
+.global typephp_os_irq_\number
+.type typephp_os_irq_\number, @function
+typephp_os_irq_\number:
+    pushq $0
+    pushq $\vector
+    jmp typephp_os_irq_common
+.size typephp_os_irq_\number, . - typephp_os_irq_\number
+.endm
+
+TYPEPHP_IRQ 0 32
+TYPEPHP_IRQ 4 36
+
+.type typephp_os_irq_common, @function
+.extern typephp_os_irq_dispatch
+typephp_os_irq_common:
+    push %rbx
+    push %rcx
+    push %rdx
+    push %rsi
+    push %rdi
+    push %rbp
+    push %r8
+    push %r9
+    push %r10
+    push %r11
+    push %r12
+    push %r13
+    push %r14
+    push %r15
+    push %rax
+
+    mov %rsp, %rdi
+    call typephp_os_irq_dispatch
+
+    pop %rax
+    pop %r15
+    pop %r14
+    pop %r13
+    pop %r12
+    pop %r11
+    pop %r10
+    pop %r9
+    pop %r8
+    pop %rbp
+    pop %rdi
+    pop %rsi
+    pop %rdx
+    pop %rcx
+    pop %rbx
+    add $16, %rsp
+    iretq
+.size typephp_os_irq_common, . - typephp_os_irq_common
+
 .type typephp_os_exception_common, @function
 .extern typephp_os_exception_dispatch
 typephp_os_exception_common:
@@ -133,14 +187,15 @@ typephp_os_exception_common:
 .global typephp_os_enter_user
 .type typephp_os_enter_user, @function
 typephp_os_enter_user:
-    # RDI = ELF entry, RSI = top of the user stack. Interrupts remain masked;
-    # SYSCALL is synchronous and the first process manager has no scheduler.
+    # RDI = ELF entry, RSI = top of the user stack. Hardware interrupts stay
+    # enabled in Ring 3 so timer and serial input can arrive while a command is
+    # running. IA32_FMASK masks them again on every SYSCALL entry.
     mov $0x1b, %ax
     mov %ax, %ds
     mov %ax, %es
     pushq $0x1b
     push %rsi
-    pushq $0x2
+    pushq $0x202
     pushq $0x23
     push %rdi
     iretq
diff --git a/examples/typephp-os/kernel/core/process.c b/examples/typephp-os/kernel/core/process.c
index 0cf9ec84..8361cf73 100644
--- a/examples/typephp-os/kernel/core/process.c
+++ b/examples/typephp-os/kernel/core/process.c
@@ -35,6 +35,14 @@ enum {
     USER_DATA_SELECTOR = 0x1b,
     KERNEL_CODE_SELECTOR = 0x08,
     TSS_SELECTOR = 0x28,
+    PIC_MASTER_COMMAND = 0x20,
+    PIC_MASTER_DATA = 0x21,
+    PIC_SLAVE_COMMAND = 0xa0,
+    PIC_SLAVE_DATA = 0xa1,
+    PIC_END_OF_INTERRUPT = 0x20,
+    PIT_CHANNEL_0 = 0x40,
+    PIT_COMMAND = 0x43,
+    TIMER_FREQUENCY = 100,
     MAX_USER_ARGUMENTS = 8,
     USER_PATH_MAX = 128,
     UTSNAME_LENGTH = 65,
@@ -216,6 +224,8 @@ extern void typephp_os_exception_11(void);
 extern void typephp_os_exception_12(void);
 extern void typephp_os_exception_13(void);
 extern void typephp_os_exception_14(void);
+extern void typephp_os_irq_0(void);
+extern void typephp_os_irq_4(void);
 extern int rename(const char *old_path, const char *new_path);
 extern uint64_t physical_page_available(void);
 extern uint64_t physical_page_total(void);
@@ -229,6 +239,7 @@ static task_state_segment tss;
 unsigned char typephp_os_syscall_stack[64u * 1024u] __attribute__((aligned(16)));
 uint64_t typephp_os_syscall_user_rsp;
 static process_state foreground_process = {.pid = 1, .cwd = "/"};
+static volatile uint64_t timer_ticks;
 
 enum {
     IA32_EFER = 0xc0000080u,
@@ -245,6 +256,57 @@ static uint64_t read_msr(uint32_t index)
     return ((uint64_t) high << 32u) | low;
 }
 
+static void outb(uint16_t port, uint8_t value)
+{
+    __asm__ volatile("outb %0, %1" : : "a"(value), "Nd"(port));
+}
+
+static void io_wait(void)
+{
+    outb(0x80, 0);
+}
+
+static void install_interrupt_controller(void)
+{
+    const uint16_t divisor = (uint16_t) (1193182u / TIMER_FREQUENCY);
+
+    /* Remap the legacy PIC away from the CPU exception vectors. */
+    outb(PIC_MASTER_COMMAND, 0x11);
+    io_wait();
+    outb(PIC_SLAVE_COMMAND, 0x11);
+    io_wait();
+    outb(PIC_MASTER_DATA, 0x20);
+    io_wait();
+    outb(PIC_SLAVE_DATA, 0x28);
+    io_wait();
+    outb(PIC_MASTER_DATA, 0x04);
+    io_wait();
+    outb(PIC_SLAVE_DATA, 0x02);
+    io_wait();
+    outb(PIC_MASTER_DATA, 0x01);
+    io_wait();
+    outb(PIC_SLAVE_DATA, 0x01);
+    io_wait();
+
+    /* A 100 Hz periodic PIT is sufficient for the single-task sleep ABI. */
+    outb(PIT_COMMAND, 0x36);
+    outb(PIT_CHANNEL_0, (uint8_t) divisor);
+    outb(PIT_CHANNEL_0, (uint8_t) (divisor >> 8u));
+    typephp_os_console_enable_interrupts();
+
+    /* IRQ0 (PIT) and IRQ4 (COM1) only. The slave PIC stays fully masked. */
+    outb(PIC_SLAVE_DATA, 0xff);
+    outb(PIC_MASTER_DATA, (uint8_t) ~(UINT8_C(1) | UINT8_C(1) << 4u));
+}
+
+static void pic_end_of_interrupt(unsigned int irq)
+{
+    if (irq >= 8u) {
+        outb(PIC_SLAVE_COMMAND, PIC_END_OF_INTERRUPT);
+    }
+    outb(PIC_MASTER_COMMAND, PIC_END_OF_INTERRUPT);
+}
+
 static void write_msr(uint32_t index, uint64_t value)
 {
     __asm__ volatile("wrmsr" : : "c"(index), "a"((uint32_t) value),
@@ -348,6 +410,8 @@ static void install_descriptor_tables(void)
     install_idt_gate(12, typephp_os_exception_12, 0x8e);
     install_idt_gate(13, typephp_os_exception_13, 0x8e);
     install_idt_gate(14, typephp_os_exception_14, 0x8e);
+    install_idt_gate(32, typephp_os_irq_0, 0x8e);
+    install_idt_gate(36, typephp_os_irq_4, 0x8e);
     pointer.limit = sizeof(idt) - 1u;
     pointer.base = (uint64_t) (uintptr_t) idt;
     __asm__ volatile("lidt %0" : : "m"(pointer) : "memory");
@@ -362,6 +426,7 @@ static void install_descriptor_tables(void)
     write_msr(IA32_LSTAR, (uint64_t) (uintptr_t) typephp_os_syscall_entry);
     write_msr(IA32_FMASK, UINT64_C(0x700)); /* TF, IF and DF */
     write_msr(IA32_EFER, read_msr(IA32_EFER) | UINT64_C(1));
+    install_interrupt_controller();
 }
 
 static int read_exact(int fd, void *buffer, size_t size)
@@ -790,6 +855,7 @@ static long syscall_gettimeofday(user_timeval *result)
 
 static long syscall_clock(int clock_id, user_timespec *result, int resolution)
 {
+    uint64_t ticks;
     if (clock_id != 0 && clock_id != 1) {
         return -EINVAL;
     }
@@ -799,8 +865,66 @@ static long syscall_clock(int clock_id, user_timespec *result, int resolution)
     if (!user_buffer(result, sizeof(*result))) {
         return -EFAULT;
     }
-    result->seconds = resolution ? 1 : typephp_os_time_seconds();
-    result->nanoseconds = 0;
+    if (resolution) {
+        result->seconds = clock_id == 0 ? 1 : 0;
+        result->nanoseconds = clock_id == 0
+            ? 0
+            : 1000000000L / TIMER_FREQUENCY;
+        return 0;
+    }
+    if (clock_id == 0) {
+        result->seconds = typephp_os_time_seconds();
+        result->nanoseconds = 0;
+        return 0;
+    }
+    ticks = timer_ticks;
+    result->seconds = (long) (ticks / TIMER_FREQUENCY);
+    result->nanoseconds = (long) (ticks % TIMER_FREQUENCY)
+        * (1000000000L / TIMER_FREQUENCY);
+    return 0;
+}
+
+static long syscall_nanosleep(
+    const user_timespec *requested, user_timespec *remaining)
+{
+    uint64_t seconds;
+    uint64_t subsecond_ticks;
+    uint64_t duration_ticks;
+    uint64_t deadline;
+    long nanoseconds;
+
+    if (!user_buffer(requested, sizeof(*requested))) {
+        return -EFAULT;
+    }
+    if (remaining != 0 && !user_buffer(remaining, sizeof(*remaining))) {
+        return -EFAULT;
+    }
+    if (requested->seconds < 0 || requested->nanoseconds < 0
+        || requested->nanoseconds >= 1000000000L) {
+        return -EINVAL;
+    }
+    seconds = (uint64_t) requested->seconds;
+    nanoseconds = requested->nanoseconds;
+    subsecond_ticks = ((uint64_t) nanoseconds
+        + (1000000000u / TIMER_FREQUENCY) - 1u)
+        / (1000000000u / TIMER_FREQUENCY);
+    if (seconds > (UINT64_MAX - subsecond_ticks) / TIMER_FREQUENCY) {
+        return -EINVAL;
+    }
+    duration_ticks = seconds * TIMER_FREQUENCY + subsecond_ticks;
+    if (duration_ticks > INT64_MAX) {
+        return -EINVAL;
+    }
+    deadline = timer_ticks + duration_ticks;
+    while ((int64_t) (timer_ticks - deadline) < 0) {
+        /* The current single foreground process sleeps inside its syscall.
+         * IRQ0 advances timer_ticks and wakes HLT; no scheduler is required. */
+        __asm__ volatile("sti; hlt; cli" : : : "memory");
+    }
+    if (remaining != 0) {
+        remaining->seconds = 0;
+        remaining->nanoseconds = 0;
+    }
     return 0;
 }
 
@@ -1199,6 +1323,22 @@ void typephp_os_exception_dispatch(exception_frame *frame)
     restore_shell_after_fault(frame);
 }
 
+void typephp_os_irq_dispatch(exception_frame *frame)
+{
+    switch (frame->vector) {
+    case 32:
+        ++timer_ticks;
+        pic_end_of_interrupt(0);
+        return;
+    case 36:
+        typephp_os_console_interrupt();
+        pic_end_of_interrupt(4);
+        return;
+    default:
+        panic("unexpected hardware interrupt\n");
+    }
+}
+
 long typephp_os_syscall_dispatch(syscall_frame *frame)
 {
     switch (frame->rax) {
@@ -1255,6 +1395,9 @@ long typephp_os_syscall_dispatch(syscall_frame *frame)
     case TYPEPHP_SYS_ACCESS:
         return syscall_access_path(AT_FDCWD, (const char *) frame->rdi,
             (int) frame->rsi, 0);
+    case TYPEPHP_SYS_NANOSLEEP:
+        return syscall_nanosleep((const user_timespec *) frame->rdi,
+            (user_timespec *) frame->rsi);
     case TYPEPHP_SYS_GETPID:
     case TYPEPHP_SYS_GETTID:
         return (long) foreground_process.pid;
diff --git a/examples/typephp-os/user/README.md b/examples/typephp-os/user/README.md
index 3192d72f..94cbfba1 100644
--- a/examples/typephp-os/user/README.md
+++ b/examples/typephp-os/user/README.md
@@ -46,7 +46,7 @@ logic, while C/C++ is limited to the syscall or PHPX boundary.
 The current shared userspace runtime provides `syscall`, `read`, `write`, `openat`,
 `open`, `close`, `lseek`, `getcwd`, `chdir`, `mkdir`, `rmdir`, `unlink`,
 `rename`, `stat`, `lstat`, `fstat`, `access`, `fsync`, `fdatasync`, `truncate`,
-`ftruncate`, `time`, `gettimeofday`, `clock_gettime`, `clock_getres`, `uname`,
+`ftruncate`, `time`, `gettimeofday`, `clock_gettime`, `clock_getres`, `nanosleep`, `sleep`, `uname`,
 `getpid`, `getppid`, `gettid`, the root UID/GID queries, `brk`, `sbrk`, `mmap`,
 `mprotect`, `munmap`, `opendir`, `fdopendir`, `readdir`, `rewinddir`,
 `closedir`, `dirfd`, the `F_GETFD`/`F_SETFD`/`F_GETFL`/`F_SETFL` subset of
@@ -85,7 +85,8 @@ The kernel additionally accepts Linux x86-64 `newfstatat`, `faccessat`,
 metadata uses the Linux x86-64 144-byte `struct stat`
 layout. FAT16 currently has no owners, ACLs, symlinks, executable file bit, or
 sub-second timestamps: UID/GID are always root, ordinary files are `0666`,
-directories are `0777`, and clock resolution is one second.
+directories are `0777`. Wall-clock values currently retain one-second RTC
+resolution; the monotonic clock and sleeping use the 100 Hz PIT.
 
 `rename()` currently accepts only source and destination paths with the same
 parent directory and does not replace an existing entry. Its transport uses a
diff --git a/examples/typephp-os/user/cmd/systest.c b/examples/typephp-os/user/cmd/systest.c
index b5e1d7de..7f7ac154 100644
--- a/examples/typephp-os/user/cmd/systest.c
+++ b/examples/typephp-os/user/cmd/systest.c
@@ -39,7 +39,9 @@ int main(int argc, char **argv)
     struct timeval wall;
     struct timespec realtime;
     struct timespec monotonic;
+    struct timespec after_sleep;
     struct timespec resolution;
+    const struct timespec sleep_duration = {0, 30000000};
     struct winsize window;
     DIR *directory;
     struct dirent *entry;
@@ -113,10 +115,18 @@ int main(int argc, char **argv)
         || clock_gettime(CLOCK_REALTIME, &realtime) != 0
         || clock_gettime(CLOCK_MONOTONIC, &monotonic) != 0
         || clock_getres(CLOCK_MONOTONIC, &resolution) != 0
-        || realtime.tv_sec <= 0 || monotonic.tv_sec <= 0
-        || resolution.tv_sec != 1 || resolution.tv_nsec != 0) {
+        || realtime.tv_sec <= 0 || monotonic.tv_nsec < 0
+        || monotonic.tv_nsec >= 1000000000L
+        || resolution.tv_sec != 0 || resolution.tv_nsec != 10000000L) {
         return fail("clock ABI");
     }
+    if (nanosleep(&sleep_duration, NULL) != 0
+        || clock_gettime(CLOCK_MONOTONIC, &after_sleep) != 0
+        || after_sleep.tv_sec < monotonic.tv_sec
+        || (after_sleep.tv_sec == monotonic.tv_sec
+            && after_sleep.tv_nsec - monotonic.tv_nsec < 20000000L)) {
+        return fail("interruptible nanosleep");
+    }
 
     (void) write(STDOUT_FILENO, "basic syscalls: OK\n",
         sizeof("basic syscalls: OK\n") - 1);
diff --git a/examples/typephp-os/user/include/sys/syscall.h b/examples/typephp-os/user/include/sys/syscall.h
index 8da9b579..01f2ae06 100644
--- a/examples/typephp-os/user/include/sys/syscall.h
+++ b/examples/typephp-os/user/include/sys/syscall.h
@@ -16,6 +16,7 @@
 #define SYS_brk TYPEPHP_SYS_BRK
 #define SYS_ioctl TYPEPHP_SYS_IOCTL
 #define SYS_access TYPEPHP_SYS_ACCESS
+#define SYS_nanosleep TYPEPHP_SYS_NANOSLEEP
 #define SYS_getpid TYPEPHP_SYS_GETPID
 #define SYS_exit TYPEPHP_SYS_EXIT
 #define SYS_uname TYPEPHP_SYS_UNAME
diff --git a/examples/typephp-os/user/include/time.h b/examples/typephp-os/user/include/time.h
index 13282d30..f50643cc 100644
--- a/examples/typephp-os/user/include/time.h
+++ b/examples/typephp-os/user/include/time.h
@@ -14,5 +14,6 @@ struct timespec {
 time_t time(time_t *result);
 int clock_gettime(clockid_t clock_id, struct timespec *value);
 int clock_getres(clockid_t clock_id, struct timespec *value);
+int nanosleep(const struct timespec *duration, struct timespec *remaining);
 
 #endif
diff --git a/examples/typephp-os/user/include/unistd.h b/examples/typephp-os/user/include/unistd.h
index b7d64c6a..4908ff12 100644
--- a/examples/typephp-os/user/include/unistd.h
+++ b/examples/typephp-os/user/include/unistd.h
@@ -30,6 +30,7 @@ uid_t getuid(void);
 uid_t geteuid(void);
 gid_t getgid(void);
 gid_t getegid(void);
+unsigned int sleep(unsigned int seconds);
 int brk(void *address);
 void *sbrk(intptr_t increment);
 void _exit(int status) __attribute__((noreturn));
diff --git a/examples/typephp-os/user/runtime/host.cc b/examples/typephp-os/user/runtime/host.cc
index 1ff1cfdb..d3ffd455 100644
--- a/examples/typephp-os/user/runtime/host.cc
+++ b/examples/typephp-os/user/runtime/host.cc
@@ -4,6 +4,7 @@
 #include <cstdint>
 #include <cstring>
 #include <sys/syscall.h>
+#include <time.h>
 #include <unistd.h>
 
 extern "C" int typephp_nano_project_main();
@@ -54,17 +55,23 @@ extern "C" void php_nano_host_system_time(
 
 extern "C" std::uint64_t php_nano_host_monotonic_nanoseconds()
 {
-    return static_cast<std::uint64_t>(syscall(SYS_time, nullptr))
-        * UINT64_C(1000000000);
+    timespec value{};
+    if (clock_gettime(CLOCK_MONOTONIC, &value) != 0) {
+        typephp_os_panic("unable to read the monotonic clock");
+    }
+    return static_cast<std::uint64_t>(value.tv_sec) * UINT64_C(1000000000)
+        + static_cast<std::uint64_t>(value.tv_nsec);
 }
 
 extern "C" void php_nano_host_sleep(
     std::uint64_t seconds, std::uint32_t nanoseconds)
 {
-    const auto now = static_cast<std::uint64_t>(syscall(SYS_time, nullptr));
-    const auto deadline = now + seconds + (nanoseconds != 0 ? 1u : 0u);
-    while (static_cast<std::uint64_t>(syscall(SYS_time, nullptr)) < deadline) {
-        __asm__ volatile("pause");
+    const timespec duration{
+        static_cast<time_t>(seconds),
+        static_cast<long>(nanoseconds),
+    };
+    if (nanosleep(&duration, nullptr) != 0) {
+        typephp_os_panic("unable to sleep");
     }
 }
 
diff --git a/examples/typephp-os/user/runtime/posix.c b/examples/typephp-os/user/runtime/posix.c
index dc1236fa..28602ae5 100644
--- a/examples/typephp-os/user/runtime/posix.c
+++ b/examples/typephp-os/user/runtime/posix.c
@@ -142,18 +142,16 @@ int clock_getres(clockid_t clock_id, struct timespec *value)
 
 unsigned int sleep(unsigned int seconds)
 {
-    const time_t deadline = time(NULL) + seconds;
-    while (time(NULL) < deadline) {
-        __asm__ volatile("pause");
-    }
-    return 0;
+    struct timespec duration = {(time_t) seconds, 0};
+    struct timespec remaining = {0, 0};
+    return nanosleep(&duration, &remaining) == 0
+        ? 0
+        : (unsigned int) remaining.tv_sec + (remaining.tv_nsec != 0);
 }
 
 int nanosleep(const struct timespec *duration, struct timespec *remaining)
 {
-    (void) remaining;
-    sleep((unsigned int) duration->tv_sec + (duration->tv_nsec != 0));
-    return 0;
+    return (int) syscall(TYPEPHP_SYS_NANOSLEEP, duration, remaining);
 }
 
 int uname(struct utsname *value)