diff --git a/third_party/lyra/toolchain/android/BUILD.tpl b/third_party/lyra/toolchain/android/BUILD.tpl
index a459ad79..3995fac1 100644
--- a/third_party/lyra/toolchain/android/BUILD.tpl
+++ b/third_party/lyra/toolchain/android/BUILD.tpl
@@ -93,6 +93,7 @@ cc_toolchain_config(
         "-D_LIBCPP_ABI_NAMESPACE=Cr",
         "-D_LIBCPP_ABI_VERSION=2",
         "-D_LIBCPP_DISABLE_AVAILABILITY",
+        '-D_LIBCPP_HARDENING_MODE=_LIBCPP_HARDENING_MODE_EXTENSIVE',
         "-fexperimental-relative-c++-abi-vtables",
         "-fexceptions",
     ],
diff --git a/third_party/lyra/toolchain/linux_x86_64/BUILD.tpl b/third_party/lyra/toolchain/linux_x86_64/BUILD.tpl
index 56a5aa87..6052c5aa 100644
--- a/third_party/lyra/toolchain/linux_x86_64/BUILD.tpl
+++ b/third_party/lyra/toolchain/linux_x86_64/BUILD.tpl
@@ -213,6 +213,7 @@ cc_toolchain_config(
         "-D_LIBCPP_ABI_NAMESPACE=Cr",
         "-D_LIBCPP_ABI_VERSION=2",
         "-D_LIBCPP_DISABLE_AVAILABILITY",
+        '-D_LIBCPP_HARDENING_MODE=_LIBCPP_HARDENING_MODE_EXTENSIVE',
     ],
     link_flags = [
         "-Wl,-no-as-needed",