diff --git a/include/kernel.h b/include/kernel.h
index 815f1516077..0d6e9d72c66 100644
--- a/include/kernel.h
+++ b/include/kernel.h
@@ -211,18 +211,6 @@ extern int k_thread_cancel(k_tid_t thread);
  */
 extern void k_thread_abort(k_tid_t thread);
 
-#define K_THREAD_GROUP_EXE 0x1
-#define K_THREAD_GROUP_SYS 0x2
-#define K_THREAD_GROUP_FPU 0x4
-
-/* XXX - doesn't work because CONFIG_ARCH is a string */
-#if 0
-/* arch-specific groups */
-#if CONFIG_ARCH == "x86"
-#define K_THREAD_GROUP_SSE 0x4
-#endif
-#endif
-
 #ifdef CONFIG_SYS_CLOCK_EXISTS
 #define _THREAD_TIMEOUT_INIT(obj) \
 	(obj).nano_timeout = { \
diff --git a/include/legacy.h b/include/legacy.h
index 110b45a32c9..2b0e7d17d6b 100644
--- a/include/legacy.h
+++ b/include/legacy.h
@@ -48,6 +48,13 @@
 /* end-of-list, mostly used for semaphore groups */
 #define ENDLIST K_END
 
+/* pre-defined task groups */
+#define K_TASK_GROUP_EXE 0x1
+#define K_TASK_GROUP_SYS 0x2
+#define K_TASK_GROUP_FPU 0x4
+/* the following is for x86 architecture only */
+#define K_TASK_GROUP_SSE 0x8
+
 /* pipe amount of content to receive (0+, 1+, all) */
 typedef enum {
 	_0_TO_N = 0x0,
diff --git a/kernel/unified/thread.c b/kernel/unified/thread.c
index 02848603c07..127892f88ee 100644
--- a/kernel/unified/thread.c
+++ b/kernel/unified/thread.c
@@ -374,8 +374,8 @@ void _init_static_threads(void)
 	}
 
 	k_sched_lock();
-	/* Start all (legacy) threads that are part of the EXE group */
-	_k_thread_group_op(K_THREAD_GROUP_EXE, _k_thread_single_start);
+	/* Start all (legacy) threads that are part of the EXE task group */
+	_k_thread_group_op(K_TASK_GROUP_EXE, _k_thread_single_start);
 
 	/*
 	 * Non-legacy static threads may be started immediately or after a