diff --git a/CI/conan/base/apple b/CI/conan/base/apple
index 18655d38b..bdb33e3e6 100644
--- a/CI/conan/base/apple
+++ b/CI/conan/base/apple
@@ -3,6 +3,10 @@ compiler=apple-clang
 compiler.version=13
 compiler.libcxx=libc++
 build_type=Release
+
+# required for Boost.Locale in versions >= 1.81
+compiler.cppstd=11
+
 [conf]
 tools.apple:enable_bitcode = False
 tools.cmake.cmaketoolchain:generator = Ninja