diff --git a/utils/bazel/llvm-project-overlay/llvm/config.bzl b/utils/bazel/llvm-project-overlay/llvm/config.bzl
--- a/utils/bazel/llvm-project-overlay/llvm/config.bzl
+++ b/utils/bazel/llvm-project-overlay/llvm/config.bzl
@@ -85,6 +85,7 @@
     "@bazel_tools//src/conditions:darwin_arm64": native_arch_defines("AArch64", "arm64-apple-darwin"),
     "@bazel_tools//src/conditions:darwin_x86_64": native_arch_defines("X86", "x86_64-unknown-darwin"),
     "@bazel_tools//src/conditions:linux_aarch64": native_arch_defines("AArch64", "aarch64-unknown-linux-gnu"),
+    "@bazel_tools//src/conditions:linux_s390x": native_arch_defines("SystemZ", "systemz-unknown-linux_gnu"),
     "//conditions:default": native_arch_defines("X86", "x86_64-unknown-linux-gnu"),
 }) + [
     # These shouldn't be needed by the C++11 standard, but are for some