diff --git a/crypto/CMakeLists.txt b/crypto/CMakeLists.txt
index c427b20..ef47623 100644
--- a/crypto/CMakeLists.txt
+++ b/crypto/CMakeLists.txt
@@ -202,9 +202,7 @@
   rand_extra/rand_extra.c
   rand_extra/windows.c
   rc4/rc4.c
-  refcount_c11.c
-  refcount_no_threads.c
-  refcount_win.c
+  refcount.c
   rsa_extra/rsa_asn1.c
   rsa_extra/rsa_crypt.c
   rsa_extra/rsa_print.c
diff --git a/crypto/internal.h b/crypto/internal.h
index 5c04735..00f0582 100644
--- a/crypto/internal.h
+++ b/crypto/internal.h
@@ -155,6 +155,32 @@
 #if defined(OPENSSL_THREADS) && !defined(OPENSSL_PTHREADS) && \
     defined(OPENSSL_WINDOWS)
 #define OPENSSL_WINDOWS_THREADS
+#endif
+
+// Determine the atomics implementation to use with C.
+#if !defined(__cplusplus)
+#if !defined(OPENSSL_C11_ATOMIC) && defined(OPENSSL_THREADS) &&   \
+    !defined(__STDC_NO_ATOMICS__) && defined(__STDC_VERSION__) && \
+    __STDC_VERSION__ >= 201112L
+#define OPENSSL_C11_ATOMIC
+#endif
+
+// Older MSVC does not support C11 atomics, so we fallback to the Windows APIs.
+// When both are available (e.g. clang-cl), we prefer the C11 ones. The Windows
+// APIs don't allow some operations to be implemented as efficiently. This can
+// be removed once we can rely on
+// https://devblogs.microsoft.com/cppblog/c11-atomics-in-visual-studio-2022-version-17-5-preview-2/
+#if !defined(OPENSSL_C11_ATOMIC) && defined(OPENSSL_THREADS) && \
+    defined(OPENSSL_WINDOWS)
+#define OPENSSL_WINDOWS_ATOMIC
+#endif
+#endif  // !__cplusplus
+
+#if defined(OPENSSL_C11_ATOMIC)
+#include <stdatomic.h>
+#endif
+
+#if defined(OPENSSL_WINDOWS_THREADS) || defined(OPENSSL_WINDOWS_ATOMIC)
 OPENSSL_MSVC_PRAGMA(warning(push, 3))
 #include <windows.h>
 OPENSSL_MSVC_PRAGMA(warning(pop))
@@ -539,33 +565,102 @@
 OPENSSL_EXPORT void CRYPTO_once(CRYPTO_once_t *once, void (*init)(void));
 
 
-// Reference counting.
+// Atomics.
+//
+// The following functions provide an API analogous to <stdatomic.h> from C11
+// and abstract between a few variations on atomics we need to support.
 
-// Automatically enable C11 atomics if implemented.
-#if !defined(OPENSSL_C11_ATOMIC) && defined(OPENSSL_THREADS) &&   \
-    !defined(__STDC_NO_ATOMICS__) && defined(__STDC_VERSION__) && \
-    __STDC_VERSION__ >= 201112L
-#define OPENSSL_C11_ATOMIC
-#endif
+#if defined(__cplusplus)
 
-// Older MSVC does not support C11 atomics, so we fallback to the Windows APIs.
-// This can be removed once we can rely on
-// https://devblogs.microsoft.com/cppblog/c11-atomics-in-visual-studio-2022-version-17-5-preview-2/
-#if !defined(OPENSSL_C11_ATOMIC) && defined(OPENSSL_THREADS) && \
-    defined(OPENSSL_WINDOWS)
-#define OPENSSL_WINDOWS_ATOMIC
-#endif
+// In C++, we can't easily detect whether C will use |OPENSSL_C11_ATOMIC| or
+// |OPENSSL_WINDOWS_ATOMIC|. Instead, we define a layout-compatible type without
+// the corresponding functions. When we can rely on C11 atomics in MSVC, that
+// will no longer be a concern.
+typedef uint32_t CRYPTO_atomic_u32;
+
+#elif defined(OPENSSL_C11_ATOMIC)
+
+typedef _Atomic uint32_t CRYPTO_atomic_u32;
+
+// This should be const, but the |OPENSSL_WINDOWS_ATOMIC| implementation is not
+// const due to Windows limitations. When we can rely on C11 atomics, make this
+// const-correct.
+OPENSSL_INLINE uint32_t CRYPTO_atomic_load_u32(CRYPTO_atomic_u32 *val) {
+  return atomic_load(val);
+}
+
+OPENSSL_INLINE int CRYPTO_atomic_compare_exchange_weak_u32(
+    CRYPTO_atomic_u32 *val, uint32_t *expected, uint32_t desired) {
+  return atomic_compare_exchange_weak(val, expected, desired);
+}
+
+#elif defined(OPENSSL_WINDOWS_ATOMIC)
+
+typedef LONG CRYPTO_atomic_u32;
+
+OPENSSL_INLINE uint32_t CRYPTO_atomic_load_u32(volatile CRYPTO_atomic_u32 *val) {
+  // This is not ideal because it still writes to a cacheline. MSVC is not able
+  // to optimize this to a true atomic read, and Windows does not provide an
+  // InterlockedLoad function.
+  //
+  // The Windows documentation [1] does say "Simple reads and writes to
+  // properly-aligned 32-bit variables are atomic operations", but this is not
+  // phrased in terms of the C11 and C++11 memory models, and indeed a read or
+  // write seems to produce slightly different code on MSVC than a sequentially
+  // consistent std::atomic::load in C++. Moreover, it is unclear if non-MSVC
+  // compilers on Windows provide the same guarantees. Thus we avoid relying on
+  // this and instead still use an interlocked function. This is still
+  // preferable a global mutex, and eventually this code will be replaced by
+  // [2]. Additionally, on clang-cl, we'll use the |OPENSSL_C11_ATOMIC| path.
+  //
+  // [1] https://learn.microsoft.com/en-us/windows/win32/sync/interlocked-variable-access
+  // [2] https://devblogs.microsoft.com/cppblog/c11-atomics-in-visual-studio-2022-version-17-5-preview-2/
+  return (uint32_t)InterlockedCompareExchange(val, 0, 0);
+}
+
+OPENSSL_INLINE int CRYPTO_atomic_compare_exchange_weak_u32(
+    volatile CRYPTO_atomic_u32 *val, uint32_t *expected32, uint32_t desired) {
+  LONG expected = (LONG)*expected32;
+  LONG actual = InterlockedCompareExchange(val, (LONG)desired, expected);
+  *expected32 = (uint32_t)actual;
+  return actual == expected;
+}
+
+#elif !defined(OPENSSL_THREADS)
+
+typedef uint32_t CRYPTO_atomic_u32;
+
+OPENSSL_INLINE uint32_t CRYPTO_atomic_load_u32(CRYPTO_atomic_u32 *val) {
+  return *val;
+}
+
+OPENSSL_INLINE int CRYPTO_atomic_compare_exchange_weak_u32(
+    CRYPTO_atomic_u32 *val, uint32_t *expected, uint32_t desired) {
+  if (*val != *expected) {
+    *expected = *val;
+    return 0;
+  }
+  *val = desired;
+  return 1;
+}
+
+#else
 
 // Require some atomics implementation. Contact BoringSSL maintainers if you
 // have a platform with fails this check.
-//
-// Note this check can only be done in C. From C++, we don't know whether the
-// corresponding C mode would support C11 atomics.
-#if !defined(__cplusplus) && defined(OPENSSL_THREADS) && \
-    !defined(OPENSSL_C11_ATOMIC) && !defined(OPENSSL_WINDOWS_ATOMIC)
 #error "Thread-compatible configurations require atomics"
+
 #endif
 
+// See the comment in the |__cplusplus| section above.
+static_assert(sizeof(CRYPTO_atomic_u32) == sizeof(uint32_t),
+              "CRYPTO_atomic_u32 does not match uint32_t size");
+static_assert(alignof(CRYPTO_atomic_u32) == alignof(uint32_t),
+              "CRYPTO_atomic_u32 does not match uint32_t alignment");
+
+
+// Reference counting.
+
 // CRYPTO_REFCOUNT_MAX is the value at which the reference count saturates.
 #define CRYPTO_REFCOUNT_MAX 0xffffffff
 
diff --git a/crypto/refcount_c11.c b/crypto/refcount.c
similarity index 66%
rename from crypto/refcount_c11.c
rename to crypto/refcount.c
index a1781c6..74ebdd7 100644
--- a/crypto/refcount_c11.c
+++ b/crypto/refcount.c
@@ -14,39 +14,35 @@
 
 #include "internal.h"
 
-
-#if defined(OPENSSL_C11_ATOMIC)
-
 #include <assert.h>
 #include <stdalign.h>
-#include <stdatomic.h>
 #include <stdlib.h>
 
 
 // See comment above the typedef of CRYPTO_refcount_t about these tests.
-static_assert(alignof(CRYPTO_refcount_t) == alignof(_Atomic CRYPTO_refcount_t),
-              "_Atomic alters the needed alignment of a reference count");
-static_assert(sizeof(CRYPTO_refcount_t) == sizeof(_Atomic CRYPTO_refcount_t),
-              "_Atomic alters the size of a reference count");
+static_assert(alignof(CRYPTO_refcount_t) == alignof(CRYPTO_atomic_u32),
+              "CRYPTO_refcount_t does not match CRYPTO_atomic_u32 alignment");
+static_assert(sizeof(CRYPTO_refcount_t) == sizeof(CRYPTO_atomic_u32),
+              "CRYPTO_refcount_t does not match CRYPTO_atomic_u32 size");
 
 static_assert((CRYPTO_refcount_t)-1 == CRYPTO_REFCOUNT_MAX,
               "CRYPTO_REFCOUNT_MAX is incorrect");
 
 void CRYPTO_refcount_inc(CRYPTO_refcount_t *in_count) {
-  _Atomic CRYPTO_refcount_t *count = (_Atomic CRYPTO_refcount_t *) in_count;
-  uint32_t expected = atomic_load(count);
+  CRYPTO_atomic_u32 *count = (CRYPTO_atomic_u32 *)in_count;
+  uint32_t expected = CRYPTO_atomic_load_u32(count);
 
   while (expected != CRYPTO_REFCOUNT_MAX) {
     uint32_t new_value = expected + 1;
-    if (atomic_compare_exchange_weak(count, &expected, new_value)) {
+    if (CRYPTO_atomic_compare_exchange_weak_u32(count, &expected, new_value)) {
       break;
     }
   }
 }
 
 int CRYPTO_refcount_dec_and_test_zero(CRYPTO_refcount_t *in_count) {
-  _Atomic CRYPTO_refcount_t *count = (_Atomic CRYPTO_refcount_t *)in_count;
-  uint32_t expected = atomic_load(count);
+  CRYPTO_atomic_u32 *count = (CRYPTO_atomic_u32 *)in_count;
+  uint32_t expected = CRYPTO_atomic_load_u32(count);
 
   for (;;) {
     if (expected == 0) {
@@ -55,11 +51,10 @@
       return 0;
     } else {
       const uint32_t new_value = expected - 1;
-      if (atomic_compare_exchange_weak(count, &expected, new_value)) {
+      if (CRYPTO_atomic_compare_exchange_weak_u32(count, &expected,
+                                                  new_value)) {
         return new_value == 0;
       }
     }
   }
 }
-
-#endif  // OPENSSL_C11_ATOMIC
diff --git a/crypto/refcount_no_threads.c b/crypto/refcount_no_threads.c
deleted file mode 100644
index 096b4fa..0000000
--- a/crypto/refcount_no_threads.c
+++ /dev/null
@@ -1,42 +0,0 @@
-/* Copyright (c) 2015, Google Inc.
- *
- * Permission to use, copy, modify, and/or distribute this software for any
- * purpose with or without fee is hereby granted, provided that the above
- * copyright notice and this permission notice appear in all copies.
- *
- * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
- * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
- * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
- * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
- * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
- * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
-
-#include "internal.h"
-
-#include <assert.h>
-#include <stdlib.h>
-
-
-#if !defined(OPENSSL_THREADS)
-
-static_assert((CRYPTO_refcount_t)-1 == CRYPTO_REFCOUNT_MAX,
-              "CRYPTO_REFCOUNT_MAX is incorrect");
-
-void CRYPTO_refcount_inc(CRYPTO_refcount_t *count) {
-  if (*count < CRYPTO_REFCOUNT_MAX) {
-    (*count)++;
-  }
-}
-
-int CRYPTO_refcount_dec_and_test_zero(CRYPTO_refcount_t *count) {
-  if (*count == 0) {
-    abort();
-  }
-  if (*count < CRYPTO_REFCOUNT_MAX) {
-    (*count)--;
-  }
-  return *count == 0;
-}
-
-#endif  // !OPENSSL_THREADS
diff --git a/crypto/refcount_win.c b/crypto/refcount_win.c
deleted file mode 100644
index 7a2740b..0000000
--- a/crypto/refcount_win.c
+++ /dev/null
@@ -1,89 +0,0 @@
-/* Copyright (c) 2023, Google Inc.
- *
- * Permission to use, copy, modify, and/or distribute this software for any
- * purpose with or without fee is hereby granted, provided that the above
- * copyright notice and this permission notice appear in all copies.
- *
- * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
- * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
- * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
- * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
- * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
- * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
-
-#include "internal.h"
-
-#if defined(OPENSSL_WINDOWS_ATOMIC)
-
-#include <windows.h>
-
-
-// See comment above the typedef of CRYPTO_refcount_t about these tests.
-static_assert(alignof(CRYPTO_refcount_t) == alignof(LONG),
-              "CRYPTO_refcount_t does not match LONG alignment");
-static_assert(sizeof(CRYPTO_refcount_t) == sizeof(LONG),
-              "CRYPTO_refcount_t does not match LONG size");
-
-static_assert((CRYPTO_refcount_t)-1 == CRYPTO_REFCOUNT_MAX,
-              "CRYPTO_REFCOUNT_MAX is incorrect");
-
-static uint32_t atomic_load_u32(volatile LONG *ptr) {
-  // This is not ideal because it still writes to a cacheline. MSVC is not able
-  // to optimize this to a true atomic read, and Windows does not provide an
-  // InterlockedLoad function.
-  //
-  // The Windows documentation [1] does say "Simple reads and writes to
-  // properly-aligned 32-bit variables are atomic operations", but this is not
-  // phrased in terms of the C11 and C++11 memory models, and indeed a read or
-  // write seems to produce slightly different code on MSVC than a sequentially
-  // consistent std::atomic::load in C++. Moreover, it is unclear if non-MSVC
-  // compilers on Windows provide the same guarantees. Thus we avoid relying on
-  // this and instead still use an interlocked function. This is still
-  // preferable a global mutex, and eventually this code will be replaced by
-  // [2]. Additionally, on clang-cl, we'll use the |OPENSSL_C11_ATOMIC| path.
-  //
-  // [1] https://learn.microsoft.com/en-us/windows/win32/sync/interlocked-variable-access
-  // [2] https://devblogs.microsoft.com/cppblog/c11-atomics-in-visual-studio-2022-version-17-5-preview-2/
-  return (uint32_t)InterlockedCompareExchange(ptr, 0, 0);
-}
-
-static int atomic_compare_exchange_u32(volatile LONG *ptr, uint32_t *expected32,
-                                       uint32_t desired) {
-  LONG expected = (LONG)*expected32;
-  LONG actual = InterlockedCompareExchange(ptr, (LONG)desired, expected);
-  *expected32 = (uint32_t)actual;
-  return actual == expected;
-}
-
-void CRYPTO_refcount_inc(CRYPTO_refcount_t *in_count) {
-  volatile LONG *count = (volatile LONG *)in_count;
-  uint32_t expected = atomic_load_u32(count);
-
-  while (expected != CRYPTO_REFCOUNT_MAX) {
-    const uint32_t new_value = expected + 1;
-    if (atomic_compare_exchange_u32(count, &expected, new_value)) {
-      break;
-    }
-  }
-}
-
-int CRYPTO_refcount_dec_and_test_zero(CRYPTO_refcount_t *in_count) {
-  volatile LONG *count = (volatile LONG *)in_count;
-  uint32_t expected = atomic_load_u32(count);
-
-  for (;;) {
-    if (expected == 0) {
-      abort();
-    } else if (expected == CRYPTO_REFCOUNT_MAX) {
-      return 0;
-    } else {
-      const uint32_t new_value = expected - 1;
-      if (atomic_compare_exchange_u32(count, &expected, new_value)) {
-        return new_value == 0;
-      }
-    }
-  }
-}
-
-#endif  // OPENSSL_WINDOWS_ATOMIC
diff --git a/include/openssl/thread.h b/include/openssl/thread.h
index afa9f08..695182b 100644
--- a/include/openssl/thread.h
+++ b/include/openssl/thread.h
@@ -100,7 +100,7 @@
 // _Atomic qualifier. However, this header is included by C++ programs as well
 // as C code that might not set -std=c11. So, in practice, it's not possible to
 // do that. Instead we statically assert that the size and native alignment of
-// a plain uint32_t and an _Atomic uint32_t are equal in refcount_c11.c.
+// a plain uint32_t and an _Atomic uint32_t are equal in refcount.c.
 typedef uint32_t CRYPTO_refcount_t;