diff --git a/gloop/thread/BUILD b/gloop/thread/BUILD
index faaae547c..52c9bf00f 100644
--- a/gloop/thread/BUILD
+++ b/gloop/thread/BUILD
@@ -46,15 +46,12 @@ POSIX_PORT_DEPS = [
 
 POSIX_PORT_SOURCES = [
     "add_after_helper.cc",
-    "cpu_subcontainer.h",  # Stubbed out, private.
     "executor.cc",
     "logger.h",
     "pcqueue.h",  # private.
-    "port/cpu_subcontainer.cc",
     "python_stack_size.h",
     "timedcall.cc",
     "thread.cc",
-    "thread_options.cc",
     "threadpool.cc",
     "watchdog.h",  # private.
     "watchdog.cc",
@@ -67,7 +64,6 @@ POSIX_PORT_HEADERS = [
     "ordered-producer-consumer-queue.h",
     "thread.h",
     "threadpool.h",
-    "thread_options.h",
     "timedcall.h",
     "wait_queue_thread.h",
 ]
@@ -239,6 +235,33 @@ cc_library(
     ],
 )
 
+cc_library(
+    name = "thread_options",
+    srcs = ["thread_options.cc"],
+    hdrs = ["thread_options.h"],
+    deps = [
+        "//gloop:enforce_gloop_support",
+        "@abseil-cpp//absl/flags:flag",
+    ],
+)
+
+cc_library(
+    name = "cpu_subcontainer_stub",
+    srcs = ["cpu_subcontainer_stub.cc"],
+    hdrs = ["cpu_subcontainer.h"],
+    visibility = ["//visibility:private"],
+    deps = ["//gloop:enforce_gloop_support"],
+)
+
+cc_library(
+    name = "cpu_subcontainer",
+    hdrs = ["cpu_subcontainer.h"],
+    deps = [
+        ":cpu_subcontainer_stub",
+        "//gloop:enforce_gloop_support",
+    ],
+)
+
 cc_library(
     name = "thread",
     srcs = select({
@@ -246,19 +269,20 @@ cc_library(
             "add_after_helper.cc",
             "executor.cc",
             "logger.cc",
-            "port/cpu_subcontainer.cc",
             "stack_reclaimer.cc",
             "stack_reclaimer.h",
             "thread.cc",
-            "thread_options.cc",
             "threadpool.cc",
             "timedcall.cc",
             "watchdog.cc",
         ],
     }),
-    hdrs = ["threadlocal.h"] + select({
+    hdrs = [
+        "cpu_subcontainer.h",
+        "thread_options.h",
+        "threadlocal.h",
+    ] + select({
         "//conditions:default": POSIX_PORT_HEADERS + [
-            "cpu_subcontainer.h",
             "logger.h",
             "pcqueue.h",
             "watchdog.h",
@@ -269,12 +293,14 @@ cc_library(
     }),
     deps = [
         ":config",
+        ":cpu_subcontainer",
         ":exit_timeout_seconds",
         ":os_semaphore",
         ":prioritized_wait_queue",
         ":python_stack_size",
         ":sync_queue",
         ":thread-internal",
+        ":thread_options",
         ":threadlocal",
         ":wait_queue",
         ":wait_state",
diff --git a/gloop/thread/config.h b/gloop/thread/config.h
index c2575ecbe..52fb64de4 100644
--- a/gloop/thread/config.h
+++ b/gloop/thread/config.h
@@ -38,7 +38,6 @@
 #include <unistd.h>
 #endif
 
-#define THREAD_HAVE_CPU_SUBCONTAINERS 0
 #define THREAD_HAVE_THREAD_CONTROL 1
 
 // THREAD_HAVE_THREAD_CLASS:
diff --git a/gloop/thread/port/cpu_subcontainer.cc b/gloop/thread/cpu_subcontainer_stub.cc
similarity index 90%
rename from gloop/thread/port/cpu_subcontainer.cc
rename to gloop/thread/cpu_subcontainer_stub.cc
index b14a79f52..6e6e25ec7 100644
--- a/gloop/thread/port/cpu_subcontainer.cc
+++ b/gloop/thread/cpu_subcontainer_stub.cc
@@ -20,13 +20,9 @@
 
 // Stub implementation for unsupported platforms.
 
-#include "gloop/thread/cpu_subcontainer.h"
-
-#include "gloop/thread/config.h"
+#include <string>
 
-#if THREAD_HAVE_CPU_SUBCONTAINERS
-#error Feature macros and BUILD file are out of sync.
-#endif
+#include "gloop/thread/cpu_subcontainer.h"
 
 thread::CpuSubContainer::CpuSubContainer(const std::string& path)
     : path_(path) {}
diff --git a/gloop/thread/thread.cc b/gloop/thread/thread.cc
index 717573000..07bfc7609 100644
--- a/gloop/thread/thread.cc
+++ b/gloop/thread/thread.cc
@@ -656,7 +656,7 @@ void Thread::Start(absl::SourceLocation loc) {
 #if !defined(__Fuchsia__)
       pthread_attr_setschedpolicy(&attr, SCHED_FIFO);
 #endif
-      if (options_.sched_priority() < 0) {
+      if (options_.get_sched_priority() < 0) {
         sched_param.sched_priority = sched_get_priority_max(SCHED_FIFO) - 1;
       } else {
 #if !defined(__Fuchsia__) && !defined(__ANDROID__)
@@ -674,7 +674,7 @@ void Thread::Start(absl::SourceLocation loc) {
         // is set.
         pthread_attr_setinheritsched(&attr, PTHREAD_EXPLICIT_SCHED);
 #endif
-        sched_param.sched_priority = options_.sched_priority();
+        sched_param.sched_priority = options_.get_sched_priority();
       }
       pthread_attr_setschedparam(&attr, &sched_param);
       break;
diff --git a/gloop/thread/thread_manager.cc b/gloop/thread/thread_manager.cc
index 9f7d75cc7..e0cf995e1 100644
--- a/gloop/thread/thread_manager.cc
+++ b/gloop/thread/thread_manager.cc
@@ -1277,7 +1277,7 @@ static bool TMCanUseDefaultExecutor(const Options& options) {
   if (options.stack_size() > base.stack_size()) return false;
   if (options.guard_size() > base.guard_size()) return false;
   if (options.scheduling_policy() != base.scheduling_policy()) return false;
-  if (options.sched_priority() != base.sched_priority()) return false;
+  if (options.get_sched_priority() != base.get_sched_priority()) return false;
   if (options.nice_priority_level() != base.nice_priority_level()) return false;
   if (options.io_class() != base.io_class()) return false;
   if (options.io_priority_level() != base.io_priority_level()) return false;
diff --git a/gloop/thread/thread_options.h b/gloop/thread/thread_options.h
index 1a5baba33..bcf017f16 100644
--- a/gloop/thread/thread_options.h
+++ b/gloop/thread/thread_options.h
@@ -148,7 +148,10 @@ class Options {
     return *this;
   }
 
-  int sched_priority() const { return sched_priority_; }
+  /** Return the scheduling priority. This is named differently because some
+   *  targets define a macro named `sched_priority` in global scope.
+   */
+  int get_sched_priority() const { return sched_priority_; }
 
   //
   // CAUTION: The following methods are not for general use