diff --git a/kernel/fork.c b/kernel/fork.c
index 2852d0e76ea3..f79e3da0caaf 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -768,6 +768,7 @@ static void set_max_threads(unsigned int max_threads_suggested)
 int arch_task_struct_size __read_mostly;
 #endif
 
+#ifndef CONFIG_ARCH_TASK_STRUCT_ALLOCATOR
 static void task_struct_whitelist(unsigned long *offset, unsigned long *size)
 {
 	/* Fetch thread_struct whitelist for the architecture. */
@@ -782,6 +783,7 @@ static void task_struct_whitelist(unsigned long *offset, unsigned long *size)
 	else
 		*offset += offsetof(struct task_struct, thread);
 }
+#endif /* CONFIG_ARCH_TASK_STRUCT_ALLOCATOR */
 
 void __init fork_init(void)
 {