diff --git a/libcxx/include/__config b/libcxx/include/__config
--- a/libcxx/include/__config
+++ b/libcxx/include/__config
@@ -155,6 +155,12 @@
 #    if defined(__FreeBSD__)
 #      define _LIBCPP_DEPRECATED_ABI_DISABLE_PAIR_TRIVIAL_COPY_CTOR
 #    endif
+// For XCOFF linkers, we have problems if we see a weak hidden version of a symbol
+// in user code (like you get with -fvisibility-inlines-hidden) and then a strong def
+// in the library, so we need to always rely on the library version.
+#  if defined(_AIX)
+#    define _LIBCPP_ABI_BAD_FUNCTION_CALL_KEY_FUNCTION
+#  endif
 #  endif
 
 #  if defined(_LIBCPP_BUILDING_LIBRARY) || _LIBCPP_ABI_VERSION >= 2
diff --git a/libcxx/test/libcxx/vendor/ibm/bad_function_call.pass.cpp b/libcxx/test/libcxx/vendor/ibm/bad_function_call.pass.cpp
new file mode 100644
--- /dev/null
+++ b/libcxx/test/libcxx/vendor/ibm/bad_function_call.pass.cpp
@@ -0,0 +1,23 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// REQUIRES: target={{powerpc.*-ibm-aix.*}}
+// ADDITIONAL_COMPILE_FLAGS: -fvisibility-inlines-hidden
+
+// When there is a weak hidden symbol in user code and a strong definition
+// in the library, the XCOFF linker relies on the library version instead
+// of failing.
+#include <functional>
+
+void foo() {}
+
+int main() {
+  std::function<void()> r(foo);
+  r();
+  return 0;
+}