diff --git a/third_party/icu/BUILD.bazel b/third_party/icu/BUILD.bazel
index 36d6b9006b9..69496567ebd 100644
--- a/third_party/icu/BUILD.bazel
+++ b/third_party/icu/BUILD.bazel
@@ -44,7 +44,7 @@ cc_library(
     ]),
     copts = [
         "-DU_COMMON_IMPLEMENTATION",
-        "-DU_HAVE_STD_ATOMICS",
+        "-DU_HAVE_STD_ATOMICS",  # TODO(gunan): Remove when TF is on ICU 64+.
     ] + select({
         ":android": [
             "-fdata-sections",