diff --git a/include/boost/core/detail/assert.hpp b/include/boost/core/detail/assert.hpp
index daf5c4e4..d2d16a78 100644
--- a/include/boost/core/detail/assert.hpp
+++ b/include/boost/core/detail/assert.hpp
@@ -5,7 +5,7 @@ Copyright 2025 Glen Joseph Fernandes
 Distributed under the Boost Software License, Version 1.0.
 (http://www.boost.org/LICENSE_1_0.txt)
 */
-#undef BOOST_CORE_ASSERT
+#undef BOOST_CORE_DETAIL_ASSERT
 
 #include <cassert>
 
@@ -14,8 +14,8 @@ Distributed under the Boost Software License, Version 1.0.
     !defined(__INTEL_COMPILER) && \
     defined(__GNUC__) && \
     (__GNUC__ < 5)
-#define BOOST_CORE_ASSERT(expr) \
+#define BOOST_CORE_DETAIL_ASSERT(expr) \
    ((expr) ? void(0) : __assert_fail(#expr, __FILE__, __LINE__, 0))
 #else
-#define BOOST_CORE_ASSERT(expr) assert(expr)
+#define BOOST_CORE_DETAIL_ASSERT(expr) assert(expr)
 #endif
diff --git a/include/boost/core/span.hpp b/include/boost/core/span.hpp
index 67323682..3a602c25 100644
--- a/include/boost/core/span.hpp
+++ b/include/boost/core/span.hpp
@@ -275,18 +275,18 @@ class span {
     }
 
     constexpr span<T, dynamic_extent> first(size_type c) const {
-        return BOOST_CORE_ASSERT(c <= size()),
+        return BOOST_CORE_DETAIL_ASSERT(c <= size()),
             span<T, dynamic_extent>(s_.p, c);
     }
 
     constexpr span<T, dynamic_extent> last(size_type c) const {
-        return BOOST_CORE_ASSERT(c <= size()),
+        return BOOST_CORE_DETAIL_ASSERT(c <= size()),
             span<T, dynamic_extent>(s_.p + (s_.n - c), c);
     }
 
     constexpr span<T, dynamic_extent> subspan(size_type o,
         size_type c = dynamic_extent) const {
-        return BOOST_CORE_ASSERT(o <= size() &&
+        return BOOST_CORE_DETAIL_ASSERT(o <= size() &&
                 (c == dynamic_extent || c + o <= size())),
             span<T, dynamic_extent>(s_.p + o,
                 c == dynamic_extent ? s_.n - o : c);
@@ -305,15 +305,15 @@ class span {
     }
 
     constexpr reference operator[](size_type i) const {
-        return BOOST_CORE_ASSERT(i < size()), s_.p[i];
+        return BOOST_CORE_DETAIL_ASSERT(i < size()), s_.p[i];
     }
 
     constexpr reference front() const {
-        return BOOST_CORE_ASSERT(!empty()), *s_.p;
+        return BOOST_CORE_DETAIL_ASSERT(!empty()), *s_.p;
     }
 
     constexpr reference back() const {
-        return BOOST_CORE_ASSERT(!empty()), s_.p[s_.n - 1];
+        return BOOST_CORE_DETAIL_ASSERT(!empty()), s_.p[s_.n - 1];
     }
 
     constexpr pointer data() const noexcept {