--- src/third_party/s2/BUILD.bazel.orig
+++ src/third_party/s2/BUILD.bazel
@@ -41,6 +41,10 @@ mongo_cc_library(
         ],
         "//conditions:default": [],
     }),
+    cxxopts = select({
+        "@platforms//os:freebsd": ["-std=c++20"],
+        "//conditions:default": [],
+    }),
     includes = ["."],
     local_defines = [
         "DEBUG_MODE=false",