diff --git a/graphics/clang-uml/files/patch-CMakeLists.txt b/graphics/clang-uml/files/patch-CMakeLists.txt
new file mode 100644
index 000000000000..8223e2b19a5e
--- /dev/null
+++ b/graphics/clang-uml/files/patch-CMakeLists.txt
@@ -0,0 +1,16 @@
+https://github.com/bkryza/clang-uml/pull/449
+
+--- CMakeLists.txt.orig	2025-06-29 11:26:26 UTC
++++ CMakeLists.txt
+@@ -123,6 +123,11 @@ if(CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
+                                    -Wno-invalid-constexpr
+                                    -Wno-deprecated-anon-enum-enum-conversion)
+     endif()
++    if(CMAKE_CXX_COMPILER_VERSION VERSION_GREATER_EQUAL 21)
++        set(CUSTOM_COMPILE_OPTIONS ${CUSTOM_COMPILE_OPTIONS}
++            -Wno-preferred-type-bitfield-enum-conversion
++            -Wno-unnecessary-virtual-specifier)
++    endif()
+ endif()
+ 
+ link_directories(${LLVM_LIBRARY_DIR})