diff --git a/compiler-rt/lib/asan/asan_fuchsia.cpp b/compiler-rt/lib/asan/asan_fuchsia.cpp
--- a/compiler-rt/lib/asan/asan_fuchsia.cpp
+++ b/compiler-rt/lib/asan/asan_fuchsia.cpp
@@ -81,7 +81,7 @@
 void PlatformTSDDtor(void *tsd) { UNREACHABLE(__func__); }
 
 static inline size_t AsanThreadMmapSize() {
-  return RoundUpTo(sizeof(AsanThread), PAGE_SIZE);
+  return RoundUpTo(sizeof(AsanThread), _zx_system_get_page_size());
 }
 
 struct AsanThread::InitOptions {
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_fuchsia.cpp b/compiler-rt/lib/sanitizer_common/sanitizer_fuchsia.cpp
--- a/compiler-rt/lib/sanitizer_common/sanitizer_fuchsia.cpp
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_fuchsia.cpp
@@ -14,7 +14,6 @@
 #include "sanitizer_fuchsia.h"
 #if SANITIZER_FUCHSIA
 
-#include <limits.h>
 #include <pthread.h>
 #include <stdlib.h>
 #include <unistd.h>
@@ -69,9 +68,7 @@
   return pid;
 }
 
-int internal_dlinfo(void *handle, int request, void *p) {
-  UNIMPLEMENTED();
-}
+int internal_dlinfo(void *handle, int request, void *p) { UNIMPLEMENTED(); }
 
 uptr GetThreadSelf() { return reinterpret_cast<uptr>(thrd_current()); }
 
@@ -153,9 +150,9 @@
   CHECK_NE(MtxUnlocked, atomic_load(m, memory_order_relaxed));
 }
 
-uptr GetPageSize() { return PAGE_SIZE; }
+uptr GetPageSize() { return _zx_system_get_page_size(); }
 
-uptr GetMmapGranularity() { return PAGE_SIZE; }
+uptr GetMmapGranularity() { return _zx_system_get_page_size(); }
 
 sanitizer_shadow_bounds_t ShadowBounds;
 
@@ -168,7 +165,7 @@
 
 static void *DoAnonymousMmapOrDie(uptr size, const char *mem_type,
                                   bool raw_report, bool die_for_nomem) {
-  size = RoundUpTo(size, PAGE_SIZE);
+  size = RoundUpTo(size, GetPageSize());
 
   zx_handle_t vmo;
   zx_status_t status = _zx_vmo_create(size, 0, &vmo);
@@ -214,15 +211,14 @@
 
 uptr ReservedAddressRange::Init(uptr init_size, const char *name,
                                 uptr fixed_addr) {
-  init_size = RoundUpTo(init_size, PAGE_SIZE);
+  init_size = RoundUpTo(init_size, GetPageSize());
   DCHECK_EQ(os_handle_, ZX_HANDLE_INVALID);
   uintptr_t base;
   zx_handle_t vmar;
-  zx_status_t status =
-      _zx_vmar_allocate(
-          _zx_vmar_root_self(),
-          ZX_VM_CAN_MAP_READ | ZX_VM_CAN_MAP_WRITE | ZX_VM_CAN_MAP_SPECIFIC,
-          0, init_size, &vmar, &base);
+  zx_status_t status = _zx_vmar_allocate(
+      _zx_vmar_root_self(),
+      ZX_VM_CAN_MAP_READ | ZX_VM_CAN_MAP_WRITE | ZX_VM_CAN_MAP_SPECIFIC, 0,
+      init_size, &vmar, &base);
   if (status != ZX_OK)
     ReportMmapFailureAndDie(init_size, name, "zx_vmar_allocate", status);
   base_ = reinterpret_cast<void *>(base);
@@ -236,7 +232,7 @@
 static uptr DoMmapFixedOrDie(zx_handle_t vmar, uptr fixed_addr, uptr map_size,
                              void *base, const char *name, bool die_for_nomem) {
   uptr offset = fixed_addr - reinterpret_cast<uptr>(base);
-  map_size = RoundUpTo(map_size, PAGE_SIZE);
+  map_size = RoundUpTo(map_size, GetPageSize());
   zx_handle_t vmo;
   zx_status_t status = _zx_vmo_create(map_size, 0, &vmo);
   if (status != ZX_OK) {
@@ -264,19 +260,19 @@
 
 uptr ReservedAddressRange::Map(uptr fixed_addr, uptr map_size,
                                const char *name) {
-  return DoMmapFixedOrDie(os_handle_, fixed_addr, map_size, base_,
-                          name_, false);
+  return DoMmapFixedOrDie(os_handle_, fixed_addr, map_size, base_, name_,
+                          false);
 }
 
 uptr ReservedAddressRange::MapOrDie(uptr fixed_addr, uptr map_size,
                                     const char *name) {
-  return DoMmapFixedOrDie(os_handle_, fixed_addr, map_size, base_,
-                          name_, true);
+  return DoMmapFixedOrDie(os_handle_, fixed_addr, map_size, base_, name_, true);
 }
 
 void UnmapOrDieVmar(void *addr, uptr size, zx_handle_t target_vmar) {
-  if (!addr || !size) return;
-  size = RoundUpTo(size, PAGE_SIZE);
+  if (!addr || !size)
+    return;
+  size = RoundUpTo(size, GetPageSize());
 
   zx_status_t status =
       _zx_vmar_unmap(target_vmar, reinterpret_cast<uintptr_t>(addr), size);
@@ -316,7 +312,7 @@
 
 void *MmapAlignedOrDieOnFatalError(uptr size, uptr alignment,
                                    const char *mem_type) {
-  CHECK_GE(size, PAGE_SIZE);
+  CHECK_GE(size, GetPageSize());
   CHECK(IsPowerOfTwo(size));
   CHECK(IsPowerOfTwo(alignment));
 
@@ -356,7 +352,8 @@
             _zx_vmar_root_self(),
             ZX_VM_PERM_READ | ZX_VM_PERM_WRITE | ZX_VM_SPECIFIC_OVERWRITE,
             addr - info.base, vmo, 0, size, &new_addr);
-        if (status == ZX_OK) CHECK_EQ(new_addr, addr);
+        if (status == ZX_OK)
+          CHECK_EQ(new_addr, addr);
       }
     }
     if (status == ZX_OK && addr != map_addr)
@@ -382,8 +379,8 @@
 }
 
 void ReleaseMemoryPagesToOS(uptr beg, uptr end) {
-  uptr beg_aligned = RoundUpTo(beg, PAGE_SIZE);
-  uptr end_aligned = RoundDownTo(end, PAGE_SIZE);
+  uptr beg_aligned = RoundUpTo(beg, GetPageSize());
+  uptr end_aligned = RoundDownTo(end, GetPageSize());
   if (beg_aligned < end_aligned) {
     zx_handle_t root_vmar = _zx_vmar_root_self();
     CHECK_NE(root_vmar, ZX_HANDLE_INVALID);
@@ -421,8 +418,9 @@
     uint64_t vmo_size;
     status = _zx_vmo_get_size(vmo, &vmo_size);
     if (status == ZX_OK) {
-      if (vmo_size < max_len) max_len = vmo_size;
-      size_t map_size = RoundUpTo(max_len, PAGE_SIZE);
+      if (vmo_size < max_len)
+        max_len = vmo_size;
+      size_t map_size = RoundUpTo(max_len, GetPageSize());
       uintptr_t addr;
       status = _zx_vmar_map(_zx_vmar_root_self(), ZX_VM_PERM_READ, 0, vmo, 0,
                             map_size, &addr);
@@ -434,7 +432,8 @@
     }
     _zx_handle_close(vmo);
   }
-  if (status != ZX_OK && errno_p) *errno_p = status;
+  if (status != ZX_OK && errno_p)
+    *errno_p = status;
   return status == ZX_OK;
 }
 
@@ -508,9 +507,7 @@
   return true;
 }
 
-u32 GetNumberOfCPUs() {
-  return zx_system_get_num_cpus();
-}
+u32 GetNumberOfCPUs() { return zx_system_get_num_cpus(); }
 
 uptr GetRSS() { UNIMPLEMENTED(); }