diff --git a/include/atomic b/include/atomic
index 34a2a58b2..adffc354a 100644
--- a/include/atomic
+++ b/include/atomic
@@ -555,6 +555,9 @@ void atomic_signal_fence(memory_order m) noexcept;
 #if !defined(_LIBCPP_HAS_C_ATOMIC_IMP) && !defined(_LIBCPP_HAS_GCC_ATOMIC_IMP)
 #error <atomic> is not implemented
 #endif
+#ifdef __ALLOW_STDC_ATOMICS_IN_CXX__
+#error <stdatomic.h> is incompatible with the C++ standard library
+#endif
 
 #if _LIBCPP_STD_VER > 14
 # define __cpp_lib_atomic_is_always_lock_free 201603L
diff --git a/test/libcxx/atomics/c_compatibility.fail.cpp b/test/libcxx/atomics/c_compatibility.fail.cpp
new file mode 100644
index 000000000..092687d5b
--- /dev/null
+++ b/test/libcxx/atomics/c_compatibility.fail.cpp
@@ -0,0 +1,28 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// UNSUPPORTED: libcpp-has-no-threads
+//
+// <atomic>
+
+// Test that including <atomic> fails to compile when we want to use C atomics
+// in C++ and have corresponding macro defined.
+
+// MODULES_DEFINES: __ALLOW_STDC_ATOMICS_IN_CXX__
+#ifndef __ALLOW_STDC_ATOMICS_IN_CXX__
+#define __ALLOW_STDC_ATOMICS_IN_CXX__
+#endif
+
+#include <atomic>
+// expected-error@atomic:* {{<stdatomic.h> is incompatible with the C++ standard library}}
+
+int main()
+{
+}
+