diff --git a/libcxx/include/__cxx03/__atomic/atomic.h b/libcxx/include/__cxx03/__atomic/atomic.h
index bc4a3937ce8be..f2e849318dce2 100644
--- a/libcxx/include/__cxx03/__atomic/atomic.h
+++ b/libcxx/include/__cxx03/__atomic/atomic.h
@@ -34,9 +34,7 @@ _LIBCPP_BEGIN_NAMESPACE_STD
 
 template <class _Tp>
 struct atomic : public __atomic_base<_Tp> {
-  using __base          = __atomic_base<_Tp>;
-  using value_type      = _Tp;
-  using difference_type = value_type;
+  using __base = __atomic_base<_Tp>;
 
   _LIBCPP_HIDE_FROM_ABI atomic() _NOEXCEPT = default;
 
@@ -59,8 +57,8 @@ struct atomic : public __atomic_base<_Tp> {
 
 template <class _Tp>
 struct atomic<_Tp*> : public __atomic_base<_Tp*> {
-  using __base          = __atomic_base<_Tp*>;
-  using value_type      = _Tp*;
+  using __base = __atomic_base<_Tp*>;
+
   using difference_type = ptrdiff_t;
 
   _LIBCPP_HIDE_FROM_ABI atomic() _NOEXCEPT = default;
diff --git a/libcxx/include/__cxx03/__atomic/atomic_base.h b/libcxx/include/__cxx03/__atomic/atomic_base.h
index a2b40c6a7e6f2..d79ef7d78c343 100644
--- a/libcxx/include/__cxx03/__atomic/atomic_base.h
+++ b/libcxx/include/__cxx03/__atomic/atomic_base.h
@@ -32,6 +32,8 @@ struct __atomic_base // false
 {
   mutable __cxx_atomic_impl<_Tp> __a_;
 
+  using value_type = _Tp;
+
   _LIBCPP_HIDE_FROM_ABI bool is_lock_free() const volatile _NOEXCEPT {
     return __cxx_atomic_is_lock_free(sizeof(__cxx_atomic_impl<_Tp>));
   }
@@ -127,6 +129,8 @@ template <class _Tp>
 struct __atomic_base<_Tp, true> : public __atomic_base<_Tp, false> {
   using __base = __atomic_base<_Tp, false>;
 
+  using difference_type = typename __base::value_type;
+
   _LIBCPP_HIDE_FROM_ABI __atomic_base() _NOEXCEPT = default;
 
   _LIBCPP_HIDE_FROM_ABI __atomic_base(_Tp __d) _NOEXCEPT : __base(__d) {}
diff --git a/libcxx/test/libcxx-03/atomics/atomics.types.operations/atomics.types.operations.req/atomic_fetch_add.verify.cpp b/libcxx/test/libcxx-03/atomics/atomics.types.operations/atomics.types.operations.req/atomic_fetch_add.verify.cpp
index 320ef57dcb6f9..1bd5792d1d272 100644
--- a/libcxx/test/libcxx-03/atomics/atomics.types.operations/atomics.types.operations.req/atomic_fetch_add.verify.cpp
+++ b/libcxx/test/libcxx-03/atomics/atomics.types.operations/atomics.types.operations.req/atomic_fetch_add.verify.cpp
@@ -6,8 +6,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-// XFAIL: FROZEN-CXX03-HEADERS-FIXME
-
 // <atomic>
 
 // template <class T>
@@ -48,12 +46,12 @@ void pointer_to_incomplete_type() {
 void function_pointer() {
   {
     volatile std::atomic<void (*)(int)> fun;
-    // expected-error-re@*:* {{static assertion failed due to requirement '!is_function<void (int)>::value'{{.*}}Pointer to function isn't allowed}}
+    // expected-error-re@*:* {{static assertion failed due to requirement {{.+}}Pointer to function isn't allowed}}
     std::atomic_fetch_add(&fun, 0);
   }
   {
     std::atomic<void (*)(int)> fun;
-    // expected-error-re@*:* {{static assertion failed due to requirement '!is_function<void (int)>::value'{{.*}}Pointer to function isn't allowed}}
+    // expected-error-re@*:* {{static assertion failed due to requirement {{.+}}Pointer to function isn't allowed}}
     std::atomic_fetch_add(&fun, 0);
   }
 }
diff --git a/libcxx/test/libcxx-03/atomics/atomics.types.operations/atomics.types.operations.req/atomic_fetch_add_explicit.verify.cpp b/libcxx/test/libcxx-03/atomics/atomics.types.operations/atomics.types.operations.req/atomic_fetch_add_explicit.verify.cpp
index bdd8089feb281..bdd4a8371b121 100644
--- a/libcxx/test/libcxx-03/atomics/atomics.types.operations/atomics.types.operations.req/atomic_fetch_add_explicit.verify.cpp
+++ b/libcxx/test/libcxx-03/atomics/atomics.types.operations/atomics.types.operations.req/atomic_fetch_add_explicit.verify.cpp
@@ -6,8 +6,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-// XFAIL: FROZEN-CXX03-HEADERS-FIXME
-
 // <atomic>
 
 // template <class T>
@@ -51,12 +49,12 @@ void pointer_to_incomplete_type() {
 void function_pointer() {
   {
     volatile std::atomic<void (*)(int)> fun;
-    // expected-error-re@*:* {{static assertion failed due to requirement '!is_function<void (int)>::value'{{.*}}Pointer to function isn't allowed}}
+    // expected-error-re@*:* {{static assertion failed due to requirement {{.+}}Pointer to function isn't allowed}}
     std::atomic_fetch_add_explicit(&fun, 0, std::memory_order_relaxed);
   }
   {
     std::atomic<void (*)(int)> fun;
-    // expected-error-re@*:* {{static assertion failed due to requirement '!is_function<void (int)>::value'{{.*}}Pointer to function isn't allowed}}
+    // expected-error-re@*:* {{static assertion failed due to requirement {{.+}}Pointer to function isn't allowed}}
     std::atomic_fetch_add_explicit(&fun, 0, std::memory_order_relaxed);
   }
 }
diff --git a/libcxx/test/libcxx-03/atomics/atomics.types.operations/atomics.types.operations.req/atomic_fetch_sub.verify.cpp b/libcxx/test/libcxx-03/atomics/atomics.types.operations/atomics.types.operations.req/atomic_fetch_sub.verify.cpp
index 2c9f89891d5be..105a010313254 100644
--- a/libcxx/test/libcxx-03/atomics/atomics.types.operations/atomics.types.operations.req/atomic_fetch_sub.verify.cpp
+++ b/libcxx/test/libcxx-03/atomics/atomics.types.operations/atomics.types.operations.req/atomic_fetch_sub.verify.cpp
@@ -6,8 +6,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-// XFAIL: FROZEN-CXX03-HEADERS-FIXME
-
 // <atomic>
 
 // template <class T>
@@ -48,12 +46,12 @@ void pointer_to_incomplete_type() {
 void function_pointer() {
   {
     volatile std::atomic<void (*)(int)> fun;
-    // expected-error-re@*:* {{static assertion failed due to requirement '!is_function<void (int)>::value'{{.*}}Pointer to function isn't allowed}}
+    // expected-error-re@*:* {{static assertion failed due to requirement {{.+}}Pointer to function isn't allowed}}
     std::atomic_fetch_sub(&fun, 0);
   }
   {
     std::atomic<void (*)(int)> fun;
-    // expected-error-re@*:* {{static assertion failed due to requirement '!is_function<void (int)>::value'{{.*}}Pointer to function isn't allowed}}
+    // expected-error-re@*:* {{static assertion failed due to requirement {{.+}}Pointer to function isn't allowed}}
     std::atomic_fetch_sub(&fun, 0);
   }
 }
diff --git a/libcxx/test/libcxx-03/atomics/atomics.types.operations/atomics.types.operations.req/atomic_fetch_sub_explicit.verify.cpp b/libcxx/test/libcxx-03/atomics/atomics.types.operations/atomics.types.operations.req/atomic_fetch_sub_explicit.verify.cpp
index 88c42750b608a..1647ed3aa281f 100644
--- a/libcxx/test/libcxx-03/atomics/atomics.types.operations/atomics.types.operations.req/atomic_fetch_sub_explicit.verify.cpp
+++ b/libcxx/test/libcxx-03/atomics/atomics.types.operations/atomics.types.operations.req/atomic_fetch_sub_explicit.verify.cpp
@@ -6,8 +6,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-// XFAIL: FROZEN-CXX03-HEADERS-FIXME
-
 // <atomic>
 
 // template <class T>
@@ -51,12 +49,12 @@ void pointer_to_incomplete_type() {
 void function_pointer() {
   {
     volatile std::atomic<void (*)(int)> fun;
-    // expected-error-re@*:* {{static assertion failed due to requirement '!is_function<void (int)>::value'{{.*}}Pointer to function isn't allowed}}
+    // expected-error-re@*:* {{static assertion failed due to requirement {{.+}}Pointer to function isn't allowed}}
     std::atomic_fetch_sub_explicit(&fun, 0, std::memory_order_relaxed);
   }
   {
     std::atomic<void (*)(int)> fun;
-    // expected-error-re@*:* {{static assertion failed due to requirement '!is_function<void (int)>::value'{{.*}}Pointer to function isn't allowed}}
+    // expected-error-re@*:* {{static assertion failed due to requirement {{.+}}Pointer to function isn't allowed}}
     std::atomic_fetch_sub_explicit(&fun, 0, std::memory_order_relaxed);
   }
 }
diff --git a/libcxx/test/std/atomics/types.pass.cpp b/libcxx/test/std/atomics/types.pass.cpp
index c979392290b35..b1edec5942cc9 100644
--- a/libcxx/test/std/atomics/types.pass.cpp
+++ b/libcxx/test/std/atomics/types.pass.cpp
@@ -17,9 +17,6 @@
 //     typedef T value_type;
 // };
 
-// atomic still has a difference_type in the C++03 frozen headers
-// XFAIL: FROZEN-CXX03-HEADERS-FIXME
-
 #include <atomic>
 #include <chrono>
 #include <cstdint>