diff --git a/tools/cpp/unix_cc_toolchain_config.bzl b/tools/cpp/unix_cc_toolchain_config.bzl
index 7849348ac4be45..1a825f1fe17115 100644
--- a/tools/cpp/unix_cc_toolchain_config.bzl
+++ b/tools/cpp/unix_cc_toolchain_config.bzl
@@ -151,7 +151,6 @@ def _sanitizer_feature(name = "", specific_compile_flags = [], specific_link_fla
                 actions = all_compile_actions,
                 flag_groups = [
                     flag_group(flags = [
-                        "-O1",
                         "-fno-omit-frame-pointer",
                         "-fno-sanitize-recover=all",
                     ] + specific_compile_flags),
diff --git a/tools/osx/crosstool/cc_toolchain_config.bzl b/tools/osx/crosstool/cc_toolchain_config.bzl
index 276c3ceb6797d7..a27068f446a90a 100644
--- a/tools/osx/crosstool/cc_toolchain_config.bzl
+++ b/tools/osx/crosstool/cc_toolchain_config.bzl
@@ -2674,7 +2674,6 @@ def _impl(ctx):
                 flag_groups = [
                     flag_group(
                         flags = [
-                            "-O1",
                             "-gline-tables-only",
                             "-fno-omit-frame-pointer",
                             "-fno-sanitize-recover=all",