diff --git a/CMakeLists.txt b/CMakeLists.txt
index ee4a140..ba926a7 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -350,25 +350,6 @@ if(LLVM_TOOLCHAIN_C_LIBRARY STREQUAL llvmlibc)
       COMPONENT llvm-toolchain-llvmlibc-configs
     )
 
-    # We need to build libc-hdrgen
-    ExternalProject_Add(
-        libc_hdrgen
-        SOURCE_DIR ${llvmproject_SOURCE_DIR}/llvm
-        DEPENDS ${lib_tool_dependencies}
-        CMAKE_ARGS
-            -DLLVM_ENABLE_RUNTIMES=libc
-            -DLLVM_LIBC_FULL_BUILD=ON
-            -DCMAKE_BUILD_TYPE=Debug
-        STEP_TARGETS build install
-        BUILD_COMMAND ${CMAKE_COMMAND} --build . --target libc-hdrgen
-        INSTALL_COMMAND ${CMAKE_COMMAND} -E true
-        # Always run the build command so that incremental builds are correct.
-        BUILD_ALWAYS TRUE
-        CONFIGURE_HANDLED_BY_BUILD TRUE
-    )
-    ExternalProject_Get_property(libc_hdrgen BINARY_DIR)
-    set(LIBC_HDRGEN ${BINARY_DIR}/bin/libc-hdrgen${CMAKE_EXECUTABLE_SUFFIX})
-
     # LLVM libc lacks a configuration for AArch64, but the AArch32 one works
     # fine. However, setting the configuration for both architectures to the
     # arm config directory means the baremetal config.json is never loaded,
@@ -616,7 +597,6 @@ if(NOT PREBUILT_TARGET_LIBRARIES)
         -DENABLE_PARALLEL_LIB_CONFIG=${ENABLE_PARALLEL_LIB_CONFIG}
         -DENABLE_PARALLEL_LIB_BUILD=${ENABLE_PARALLEL_LIB_BUILD}
         -DPARALLEL_LIB_BUILD_LEVELS=${PARALLEL_LIB_BUILD_LEVELS}
-        -DLIBC_HDRGEN=${LIBC_HDRGEN}
         -DFVP_INSTALL_DIR=${FVP_INSTALL_DIR}
         -DENABLE_QEMU_TESTING=${ENABLE_QEMU_TESTING}
         -DENABLE_FVP_TESTING=${ENABLE_FVP_TESTING}
diff --git a/arm-multilib/CMakeLists.txt b/arm-multilib/CMakeLists.txt
index 84e31b0..e156871 100644
--- a/arm-multilib/CMakeLists.txt
+++ b/arm-multilib/CMakeLists.txt
@@ -32,7 +32,6 @@ set(ENABLE_VARIANTS "all" CACHE STRING "Semicolon separated list of variants to
 set(C_LIBRARY "picolibc" CACHE STRING "Which C library to use.")
 set_property(CACHE C_LIBRARY PROPERTY STRINGS picolibc newlib llvmlibc)
 set(LLVM_BINARY_DIR "" CACHE PATH "Path to LLVM toolchain build or install root.")
-set(LIBC_HDRGEN "" CACHE PATH "Path to prebuilt lbc-hdrgen if not included in LLVM binaries set by LLVM_BINARY_DIR")
 option(
     ENABLE_QEMU_TESTING
     "Enable tests that use QEMU. This option is ON by default."
@@ -83,7 +82,6 @@ endif()
 # Arguments to pass down to the library projects.
 foreach(arg
     LLVM_BINARY_DIR
-    LIBC_HDRGEN
     FVP_INSTALL_DIR
     FVP_CONFIG_DIR
 )
@@ -108,31 +106,6 @@ endif()
 # Target for any dependencies to build the runtimes project.
 add_custom_target(runtimes-depends)
 
-# If building llvm-libc, ensure libc-hdrgen is available.
-if(C_LIBRARY STREQUAL llvmlibc)
-    if(NOT LIBC_HDRGEN)
-        if(EXISTS ${LLVM_BINARY_DIR}/bin/libc-hdrgen${CMAKE_EXECUTABLE_SUFFIX})
-            set(LIBC_HDRGEN ${LLVM_BINARY_DIR}/bin/libc-hdrgen${CMAKE_EXECUTABLE_SUFFIX})
-        else()
-            ExternalProject_Add(
-                libc_hdrgen
-                SOURCE_DIR ${llvmproject_SOURCE_DIR}/llvm
-                CMAKE_ARGS
-                    -DLLVM_ENABLE_RUNTIMES=libc
-                    -DLLVM_LIBC_FULL_BUILD=ON
-                    -DCMAKE_BUILD_TYPE=Debug
-                BUILD_COMMAND ${CMAKE_COMMAND} --build . --target libc-hdrgen
-                INSTALL_COMMAND ${CMAKE_COMMAND} -E true
-                CONFIGURE_HANDLED_BY_BUILD TRUE
-            )
-            ExternalProject_Get_property(libc_hdrgen BINARY_DIR)
-            set(LIBC_HDRGEN ${BINARY_DIR}/bin/libc-hdrgen${CMAKE_EXECUTABLE_SUFFIX})
-            add_dependencies(runtimes-depends libc_hdrgen)
-        endif()
-    endif()
-    list(APPEND passthrough_dirs "-DLIBC_HDRGEN=${LIBC_HDRGEN}")
-endif()
-
 # Create one target to run all the tests.
 add_custom_target(check-${C_LIBRARY})
 add_custom_target(check-compiler-rt)
diff --git a/arm-runtimes/CMakeLists.txt b/arm-runtimes/CMakeLists.txt
index a79bd63..2d3514d 100644
--- a/arm-runtimes/CMakeLists.txt
+++ b/arm-runtimes/CMakeLists.txt
@@ -96,7 +96,6 @@ set(ENABLE_LIBC_TESTS ${ENABLE_LIBC_TESTS_def} CACHE BOOL "Enable libc tests (pi
 set(ENABLE_COMPILER_RT_TESTS ${ENABLE_COMPILER_RT_TESTS_def} CACHE BOOL "Enable compiler-rt tests.")
 set(ENABLE_LIBCXX_TESTS ${ENABLE_LIBCXX_TESTS_def} CACHE BOOL "Enable libcxx tests.")
 set(LLVM_BINARY_DIR "" CACHE PATH "Path to LLVM toolchain root to build libraries with")
-set(LIBC_HDRGEN "" CACHE PATH "Path to prebuilt lbc-hdrgen if not included in LLVM binaries set by LLVM_BINARY_DIR")
 
 # Temporary location to collect the libraries as they are built.
 set(TEMP_LIB_DIR "${CMAKE_CURRENT_BINARY_DIR}/tmp_install")
@@ -585,39 +584,14 @@ if(C_LIBRARY STREQUAL llvmlibc)
         -DCMAKE_TRY_COMPILE_TARGET_TYPE=STATIC_LIBRARY
     )
 
-    if(LIBC_HDRGEN)
-        # If libc-hdrgen is provided, there is no need to build it,
-        # but a target is still needed to satisfy the dependency.
-        add_custom_target(libc_hdrgen)
-    elseif(EXISTS ${LLVM_BINARY_DIR}/bin/libc-hdrgen${CMAKE_EXECUTABLE_SUFFIX})
-        set(LIBC_HDRGEN ${LLVM_BINARY_DIR}/bin/libc-hdrgen${CMAKE_EXECUTABLE_SUFFIX})
-        add_custom_target(libc_hdrgen)
-    else()
-        ExternalProject_Add(
-            libc_hdrgen
-            SOURCE_DIR ${llvmproject_SOURCE_DIR}/llvm
-            CMAKE_ARGS
-                -DLLVM_ENABLE_RUNTIMES=libc
-                -DLLVM_LIBC_FULL_BUILD=ON
-                -DCMAKE_BUILD_TYPE=Debug
-            BUILD_COMMAND ${CMAKE_COMMAND} --build . --target libc-hdrgen
-            INSTALL_COMMAND ${CMAKE_COMMAND} -E true
-            CONFIGURE_HANDLED_BY_BUILD TRUE
-        )
-        ExternalProject_Get_property(libc_hdrgen BINARY_DIR)
-        set(LIBC_HDRGEN ${BINARY_DIR}/bin/libc-hdrgen${CMAKE_EXECUTABLE_SUFFIX})
-    endif()
-
     ExternalProject_Add(
         llvmlibc
         SOURCE_DIR ${llvmproject_SOURCE_DIR}/runtimes
         INSTALL_DIR llvmlibc/install
-        DEPENDS libc_hdrgen
         CMAKE_ARGS
         ${compiler_launcher_cmake_args}
         ${common_llvmlibc_cmake_args}
         -DLIBC_TARGET_TRIPLE=${target_triple}
-        -DLIBC_HDRGEN_EXE=${LIBC_HDRGEN}
         -DLIBC_CONFIG_PATH=${LIBC_CFG_DIR}
         -DLIBC_CONF_TIME_64BIT=ON
         -DLLVM_CMAKE_DIR=${LLVM_BINARY_DIR}/lib/cmake/llvm