diff --git a/pkgs/development/compilers/llvm/22/clang/gnu-install-dirs.patch b/pkgs/development/compilers/llvm/22/clang/gnu-install-dirs.patch
new file mode 100644
index 000000000000..d86f269c7ab8
--- /dev/null
+++ b/pkgs/development/compilers/llvm/22/clang/gnu-install-dirs.patch
@@ -0,0 +1,71 @@
+diff --git a/cmake/modules/AddClang.cmake b/cmake/modules/AddClang.cmake
+index 4059fc3e986c..e7b414d4c767 100644
+--- a/cmake/modules/AddClang.cmake
++++ b/cmake/modules/AddClang.cmake
+@@ -134,8 +134,8 @@ macro(add_clang_library name)
+         install(TARGETS ${lib}
+           COMPONENT ${lib}
+           ${export_to_clangtargets}
+-          LIBRARY DESTINATION lib${LLVM_LIBDIR_SUFFIX}
+-          ARCHIVE DESTINATION lib${LLVM_LIBDIR_SUFFIX}
++          LIBRARY DESTINATION "${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}"
++          ARCHIVE DESTINATION "${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}"
+           RUNTIME DESTINATION "${CMAKE_INSTALL_BINDIR}")
+ 
+         if (NOT LLVM_ENABLE_IDE)
+diff --git a/lib/Headers/CMakeLists.txt b/lib/Headers/CMakeLists.txt
+index 1b96ac417bf7..cf5b590fbc1b 100644
+--- a/lib/Headers/CMakeLists.txt
++++ b/lib/Headers/CMakeLists.txt
+@@ -402,6 +402,7 @@ set(zos_wrapper_files
+ 
+ include(GetClangResourceDir)
+ get_clang_resource_dir(output_dir PREFIX ${LLVM_LIBRARY_OUTPUT_INTDIR}/.. SUBDIR include)
++set(header_install_dir ${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}/clang/${CLANG_VERSION_MAJOR}/include)
+ set(out_files)
+ set(generated_files)
+ 
+diff --git a/tools/libclang/CMakeLists.txt b/tools/libclang/CMakeLists.txt
+index b0105f5a5f79..c8298517b3d2 100644
+--- a/tools/libclang/CMakeLists.txt
++++ b/tools/libclang/CMakeLists.txt
+@@ -244,7 +244,7 @@ foreach(PythonVersion ${CLANG_PYTHON_BINDINGS_VERSIONS})
+           COMPONENT
+             libclang-python-bindings
+           DESTINATION
+-            "lib${LLVM_LIBDIR_SUFFIX}/python${PythonVersion}/site-packages")
++            "${CMAKE_INSTALL_LIBDIR}${LLVM_LIBDIR_SUFFIX}/python${PythonVersion}/site-packages")
+ endforeach()
+ if(NOT LLVM_ENABLE_IDE)
+   add_custom_target(libclang-python-bindings)
+diff --git a/tools/scan-build-py/CMakeLists.txt b/tools/scan-build-py/CMakeLists.txt
+index 84087a9fd8d2..ecf377349cb5 100644
+--- a/tools/scan-build-py/CMakeLists.txt
++++ b/tools/scan-build-py/CMakeLists.txt
+@@ -91,7 +91,7 @@ if(CLANG_INSTALL_SCANBUILDPY)
+                        DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/lib/libscanbuild/${lib})
+     list(APPEND Depends ${CMAKE_BINARY_DIR}/lib/libscanbuild/${lib})
+     install(FILES lib/libscanbuild/${lib}
+-            DESTINATION lib/libscanbuild
++            DESTINATION "${CMAKE_INSTALL_LIBDIR}/libscanbuild"
+             COMPONENT scan-build-py)
+   endforeach()
+ 
+@@ -109,7 +109,7 @@ if(CLANG_INSTALL_SCANBUILDPY)
+                        DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/lib/libscanbuild/resources/${resource})
+     list(APPEND Depends ${CMAKE_BINARY_DIR}/lib/libscanbuild/resources/${resource})
+     install(FILES lib/libscanbuild/resources/${resource}
+-            DESTINATION lib/libscanbuild/resources
++            DESTINATION "${CMAKE_INSTALL_LIBDIR}/libscanbuild/resources"
+             COMPONENT scan-build-py)
+   endforeach()
+ 
+@@ -125,7 +125,7 @@ if(CLANG_INSTALL_SCANBUILDPY)
+                        DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/lib/libear/${lib})
+     list(APPEND Depends ${CMAKE_BINARY_DIR}/lib/libear/${lib})
+     install(FILES lib/libear/${lib}
+-            DESTINATION lib/libear
++            DESTINATION "${CMAKE_INSTALL_LIBDIR}/libear"
+             COMPONENT scan-build-py)
+   endforeach()
+ 
diff --git a/pkgs/development/compilers/llvm/22/llvm/lit-shell-script-runner-set-dyld-library-path.patch b/pkgs/development/compilers/llvm/22/llvm/lit-shell-script-runner-set-dyld-library-path.patch
new file mode 100644
index 000000000000..87f7aa9c8452
--- /dev/null
+++ b/pkgs/development/compilers/llvm/22/llvm/lit-shell-script-runner-set-dyld-library-path.patch
@@ -0,0 +1,14 @@
+diff --git a/utils/lit/lit/TestRunner.py b/utils/lit/lit/TestRunner.py
+index 7a233b238f7e..23aa87fdb097 100644
+--- a/utils/lit/lit/TestRunner.py
++++ b/utils/lit/lit/TestRunner.py
+@@ -1341,6 +1341,9 @@ def executeScript(test, litConfig, tmpBase, commands, cwd):
+             f.write("@echo on\n")
+             f.write("\n@if %ERRORLEVEL% NEQ 0 EXIT\n".join(commands))
+     else:
++        if "DYLD_LIBRARY_PATH" in test.config.environment:
++            f.write(f'export DYLD_LIBRARY_PATH="{test.config.environment["DYLD_LIBRARY_PATH"]}"\n')
++
+         for i, ln in enumerate(commands):
+             match = re.fullmatch(kPdbgRegex, ln)
+             if match:
diff --git a/pkgs/development/compilers/llvm/common/patches.nix b/pkgs/development/compilers/llvm/common/patches.nix
index b97f8af6eae2..757eaf7230e5 100644
--- a/pkgs/development/compilers/llvm/common/patches.nix
+++ b/pkgs/development/compilers/llvm/common/patches.nix
@@ -1,7 +1,12 @@
 {
   "clang/gnu-install-dirs.patch" = [
+    {
+      after = "22";
+      path = ../22;
+    }
     {
       after = "19";
+      before = "22";
       path = ../19;
     }
   ];
@@ -51,8 +56,13 @@
     }
   ];
   "llvm/lit-shell-script-runner-set-dyld-library-path.patch" = [
+    {
+      after = "22";
+      path = ../22;
+    }
     {
       path = ../18;
+      before = "22";
     }
   ];
   "llvm/polly-lit-cfg-add-libs-to-dylib-path.patch" = [
diff --git a/pkgs/development/compilers/llvm/default.nix b/pkgs/development/compilers/llvm/default.nix
index 0fee751cc771..90f237dbc1db 100644
--- a/pkgs/development/compilers/llvm/default.nix
+++ b/pkgs/development/compilers/llvm/default.nix
@@ -27,9 +27,9 @@ let
     "20.1.8".officialRelease.sha256 = "sha256-ysyB/EYxi2qE9fD5x/F2zI4vjn8UDoo1Z9ukiIrjFGw=";
     "21.1.2".officialRelease.sha256 = "sha256-SgZdBL0ivfv6/4EqmPQ+I57qT2t6i/rqnm20+T1BsFY=";
     "22.0.0-git".gitRelease = {
-      rev = "8f51da369e6e7f13bea941e61b4b2c5fa81216f5";
-      rev-version = "22.0.0-unstable-2025-12-14";
-      sha256 = "sha256-9om/PWp+cjMRP+2LVhC1xCczmabNenebEMDbOytyhUA=";
+      rev = "185f5fd5ce4c65116ca8cf6df467a682ef090499";
+      rev-version = "22.0.0-unstable-2025-12-21";
+      sha256 = "sha256-NcDH3JspWmq6B3wFy4wkbAzdpsKJojrJpQyAIm7qFdQ=";
     };
   }
   // llvmVersions;