diff --git a/src/unix/core.c b/src/unix/core.c
index 9343ee72..3dd7a94c 100644
--- a/src/unix/core.c
+++ b/src/unix/core.c
@@ -233,10 +233,10 @@ int uv__getiovmax(void) {
 #if defined(IOV_MAX)
   return IOV_MAX;
 #elif defined(_SC_IOV_MAX)
-  static int iovmax_cached = -1;
+  static _Atomic int iovmax_cached = -1;
   int iovmax;
 
-  iovmax = uv__load_relaxed(&iovmax_cached);
+  iovmax = atomic_load_explicit(&iovmax_cached, memory_order_relaxed);
   if (iovmax != -1)
     return iovmax;
 
@@ -248,7 +248,7 @@ int uv__getiovmax(void) {
   if (iovmax == -1)
     iovmax = 1;
 
-  uv__store_relaxed(&iovmax_cached, iovmax);
+  atomic_store_explicit(&iovmax_cached, iovmax, memory_order_relaxed);
 
   return iovmax;
 #else
diff --git a/src/unix/fs.c b/src/unix/fs.c
index 9c8ef6cc..a54038c9 100644
--- a/src/unix/fs.c
+++ b/src/unix/fs.c
@@ -309,7 +309,7 @@ static int uv__fs_mkstemp(uv_fs_t* req) {
   static uv_once_t once = UV_ONCE_INIT;
   int r;
 #ifdef O_CLOEXEC
-  static int no_cloexec_support;
+  static _Atomic int no_cloexec_support;
 #endif
   static const char pattern[] = "XXXXXX";
   static const size_t pattern_size = sizeof(pattern) - 1;
@@ -334,7 +334,8 @@ static int uv__fs_mkstemp(uv_fs_t* req) {
   uv_once(&once, uv__mkostemp_initonce);
 
 #ifdef O_CLOEXEC
-  if (uv__load_relaxed(&no_cloexec_support) == 0 && uv__mkostemp != NULL) {
+  if (atomic_load_explicit(&no_cloexec_support, memory_order_relaxed) == 0 &&
+      uv__mkostemp != NULL) {
     r = uv__mkostemp(path, O_CLOEXEC);
 
     if (r >= 0)
@@ -347,7 +348,7 @@ static int uv__fs_mkstemp(uv_fs_t* req) {
 
     /* We set the static variable so that next calls don't even
        try to use mkostemp. */
-    uv__store_relaxed(&no_cloexec_support, 1);
+    atomic_store_explicit(&no_cloexec_support, 1, memory_order_relaxed);
   }
 #endif  /* O_CLOEXEC */
 
@@ -457,7 +458,7 @@ static ssize_t uv__fs_preadv(uv_file fd,
 
 static ssize_t uv__fs_read(uv_fs_t* req) {
 #if defined(__linux__)
-  static int no_preadv;
+  static _Atomic int no_preadv;
 #endif
   unsigned int iovmax;
   ssize_t result;
@@ -481,7 +482,7 @@ static ssize_t uv__fs_read(uv_fs_t* req) {
     result = preadv(req->file, (struct iovec*) req->bufs, req->nbufs, req->off);
 #else
 # if defined(__linux__)
-    if (uv__load_relaxed(&no_preadv)) retry:
+    if (atomic_load_explicit(&no_preadv, memory_order_relaxed)) retry:
 # endif
     {
       result = uv__fs_preadv(req->file, req->bufs, req->nbufs, req->off);
@@ -493,7 +494,7 @@ static ssize_t uv__fs_read(uv_fs_t* req) {
                       req->nbufs,
                       req->off);
       if (result == -1 && errno == ENOSYS) {
-        uv__store_relaxed(&no_preadv, 1);
+        atomic_store_explicit(&no_preadv, 1, memory_order_relaxed);
         goto retry;
       }
     }
@@ -899,14 +900,14 @@ out:
 
 #ifdef __linux__
 static unsigned uv__kernel_version(void) {
-  static unsigned cached_version;
+  static _Atomic unsigned cached_version;
   struct utsname u;
   unsigned version;
   unsigned major;
   unsigned minor;
   unsigned patch;
 
-  version = uv__load_relaxed(&cached_version);
+  version = atomic_load_explicit(&cached_version, memory_order_relaxed);
   if (version != 0)
     return version;
 
@@ -917,7 +918,7 @@ static unsigned uv__kernel_version(void) {
     return 0;
 
   version = major * 65536 + minor * 256 + patch;
-  uv__store_relaxed(&cached_version, version);
+  atomic_store_explicit(&cached_version, version, memory_order_relaxed);
 
   return version;
 }
@@ -959,10 +960,10 @@ static int uv__is_cifs_or_smb(int fd) {
 
 static ssize_t uv__fs_try_copy_file_range(int in_fd, off_t* off,
                                           int out_fd, size_t len) {
-  static int no_copy_file_range_support;
+  static _Atomic int no_copy_file_range_support;
   ssize_t r;
 
-  if (uv__load_relaxed(&no_copy_file_range_support)) {
+  if (atomic_load_explicit(&no_copy_file_range_support, memory_order_relaxed)) {
     errno = ENOSYS;
     return -1;
   }
@@ -981,7 +982,7 @@ static ssize_t uv__fs_try_copy_file_range(int in_fd, off_t* off,
       errno = ENOSYS;  /* Use fallback. */
     break;
   case ENOSYS:
-    uv__store_relaxed(&no_copy_file_range_support, 1);
+    atomic_store_explicit(&no_copy_file_range_support, 1, memory_order_relaxed);
     break;
   case EPERM:
     /* It's been reported that CIFS spuriously fails.
@@ -1530,14 +1531,14 @@ static int uv__fs_statx(int fd,
                         uv_stat_t* buf) {
   STATIC_ASSERT(UV_ENOSYS != -1);
 #ifdef __linux__
-  static int no_statx;
+  static _Atomic int no_statx;
   struct uv__statx statxbuf;
   int dirfd;
   int flags;
   int mode;
   int rc;
 
-  if (uv__load_relaxed(&no_statx))
+  if (atomic_load_explicit(&no_statx, memory_order_relaxed))
     return UV_ENOSYS;
 
   dirfd = AT_FDCWD;
@@ -1571,7 +1572,7 @@ static int uv__fs_statx(int fd,
      * implemented, rc might return 1 with 0 set as the error code in which
      * case we return ENOSYS.
      */
-    uv__store_relaxed(&no_statx, 1);
+    atomic_store_explicit(&no_statx, 1, memory_order_relaxed);
     return UV_ENOSYS;
   }
 
diff --git a/src/unix/kqueue.c b/src/unix/kqueue.c
index c68cd451..deb486ba 100644
--- a/src/unix/kqueue.c
+++ b/src/unix/kqueue.c
@@ -60,7 +60,7 @@ int uv__kqueue_init(uv_loop_t* loop) {
 
 
 #if defined(__APPLE__) && MAC_OS_X_VERSION_MAX_ALLOWED >= 1070
-static int uv__has_forked_with_cfrunloop;
+static _Atomic int uv__has_forked_with_cfrunloop;
 #endif
 
 int uv__io_fork(uv_loop_t* loop) {
@@ -82,7 +82,9 @@ int uv__io_fork(uv_loop_t* loop) {
        process. So we sidestep the issue by pretending like we never
        started it in the first place.
     */
-    uv__store_relaxed(&uv__has_forked_with_cfrunloop, 1);
+    atomic_store_explicit(&uv__has_forked_with_cfrunloop,
+                          1,
+                          memory_order_relaxed);
     uv__free(loop->cf_state);
     loop->cf_state = NULL;
   }
@@ -530,7 +532,8 @@ int uv_fs_event_start(uv_fs_event_t* handle,
   if (!(statbuf.st_mode & S_IFDIR))
     goto fallback;
 
-  if (0 == uv__load_relaxed(&uv__has_forked_with_cfrunloop)) {
+  if (0 == atomic_load_explicit(&uv__has_forked_with_cfrunloop,
+                                memory_order_relaxed)) {
     int r;
     /* The fallback fd is no longer needed */
     uv__close_nocheckstdio(fd);
@@ -565,7 +568,8 @@ int uv_fs_event_stop(uv_fs_event_t* handle) {
   uv__handle_stop(handle);
 
 #if defined(__APPLE__) && MAC_OS_X_VERSION_MAX_ALLOWED >= 1070
-  if (0 == uv__load_relaxed(&uv__has_forked_with_cfrunloop))
+  if (0 == atomic_load_explicit(&uv__has_forked_with_cfrunloop,
+                                memory_order_relaxed))
     if (handle->cf_cb != NULL)
       r = uv__fsevents_close(handle);
 #endif
diff --git a/src/unix/linux.c b/src/unix/linux.c
index 0512417a..a30f1bfb 100644
--- a/src/unix/linux.c
+++ b/src/unix/linux.c
@@ -579,7 +579,7 @@ update_timeout:
 }
 
 uint64_t uv__hrtime(uv_clocktype_t type) {
-  static clock_t fast_clock_id = -1;
+  static _Atomic clock_t fast_clock_id = -1;
   struct timespec t;
   clock_t clock_id;
 
@@ -595,7 +595,7 @@ uint64_t uv__hrtime(uv_clocktype_t type) {
   if (type != UV_CLOCK_FAST)
     goto done;
 
-  clock_id = uv__load_relaxed(&fast_clock_id);
+  clock_id = atomic_load_explicit(&fast_clock_id, memory_order_relaxed);
   if (clock_id != -1)
     goto done;
 
@@ -604,7 +604,7 @@ uint64_t uv__hrtime(uv_clocktype_t type) {
     if (t.tv_nsec <= 1 * 1000 * 1000)
       clock_id = CLOCK_MONOTONIC_COARSE;
 
-  uv__store_relaxed(&fast_clock_id, clock_id);
+  atomic_store_explicit(&fast_clock_id, clock_id, memory_order_relaxed);
 
 done:
 
diff --git a/src/uv-common.c b/src/uv-common.c
index 1031be4a..cec771fa 100644
--- a/src/uv-common.c
+++ b/src/uv-common.c
@@ -944,7 +944,7 @@ __attribute__((destructor))
 void uv_library_shutdown(void) {
   static int was_shutdown;
 
-  if (uv__load_relaxed(&was_shutdown))
+  if (uv__exchange_int_relaxed(&was_shutdown, 1))
     return;
 
   uv__process_title_cleanup();
@@ -955,7 +955,6 @@ void uv_library_shutdown(void) {
 #else
   uv__threadpool_cleanup();
 #endif
-  uv__store_relaxed(&was_shutdown, 1);
 }
 
 
diff --git a/src/uv-common.h b/src/uv-common.h
index 26d0e49b..2720121a 100644
--- a/src/uv-common.h
+++ b/src/uv-common.h
@@ -37,6 +37,10 @@
 #include "queue.h"
 #include "strscpy.h"
 
+#ifndef _MSC_VER
+# include <stdatomic.h>
+#endif
+
 #if EDOM > 0
 # define UV__ERR(x) (-(x))
 #else
@@ -61,12 +65,12 @@ extern int snprintf(char*, size_t, const char*, ...);
   void uv__static_assert(int static_assert_failed[1 - 2 * !(expr)])
 #endif
 
-#if defined(__GNUC__) && (__GNUC__ > 4 || __GNUC__ == 4 && __GNUC_MINOR__ >= 7)
-#define uv__load_relaxed(p) __atomic_load_n(p, __ATOMIC_RELAXED)
-#define uv__store_relaxed(p, v) __atomic_store_n(p, v, __ATOMIC_RELAXED)
+#ifdef _MSC_VER
+#define uv__exchange_int_relaxed(p, v)                                        \
+  InterlockedExchangeNoFence((LONG volatile*)(p), v)
 #else
-#define uv__load_relaxed(p) (*p)
-#define uv__store_relaxed(p, v) do *p = v; while (0)
+#define uv__exchange_int_relaxed(p, v)                                        \
+  atomic_exchange_explicit((_Atomic int*)(p), v, memory_order_relaxed)
 #endif
 
 #define UV__UDP_DGRAM_MAXSIZE (64 * 1024)