diff --git a/kernel/sched/ext/arena.c b/kernel/sched/ext/arena.c
index 493c2424f842..5783694ec21d 100644
--- a/kernel/sched/ext/arena.c
+++ b/kernel/sched/ext/arena.c
@@ -15,6 +15,10 @@
  * Copyright (c) 2026 Meta Platforms, Inc. and affiliates.
  * Copyright (c) 2026 Tejun Heo <tj@kernel.org>
  */
+#include <linux/genalloc.h>
+
+#include "internal.h"
+#include "arena.h"
 
 enum scx_arena_consts {
 	SCX_ARENA_MIN_ORDER		= 3,	/* 8-byte minimum sub-allocation */
diff --git a/kernel/sched/ext/arena.h b/kernel/sched/ext/arena.h
index 4f3610160102..c378ae5fbc02 100644
--- a/kernel/sched/ext/arena.h
+++ b/kernel/sched/ext/arena.h
@@ -8,6 +8,8 @@
 #ifndef _KERNEL_SCHED_EXT_ARENA_H
 #define _KERNEL_SCHED_EXT_ARENA_H
 
+#include <linux/types.h>
+
 struct scx_sched;
 
 s32 scx_arena_pool_init(struct scx_sched *sch);
diff --git a/kernel/sched/ext/cid.c b/kernel/sched/ext/cid.c
index aeaea88f34c5..af83084ec740 100644
--- a/kernel/sched/ext/cid.c
+++ b/kernel/sched/ext/cid.c
@@ -7,6 +7,9 @@
  */
 #include <linux/cacheinfo.h>
 
+#include "internal.h"
+#include "cid.h"
+
 /*
  * cid tables.
  *
diff --git a/kernel/sched/ext/cid.h b/kernel/sched/ext/cid.h
index 6e657fd147b0..41d0802c6af3 100644
--- a/kernel/sched/ext/cid.h
+++ b/kernel/sched/ext/cid.h
@@ -33,6 +33,8 @@
 #ifndef _KERNEL_SCHED_EXT_CID_H
 #define _KERNEL_SCHED_EXT_CID_H
 
+#include "internal.h"
+
 struct scx_sched;
 
 /*
diff --git a/kernel/sched/ext/ext.c b/kernel/sched/ext/ext.c
index 00fe6cc6d7e2..f3253c946764 100644
--- a/kernel/sched/ext/ext.c
+++ b/kernel/sched/ext/ext.c
@@ -6,6 +6,19 @@
  * Copyright (c) 2022 Tejun Heo <tj@kernel.org>
  * Copyright (c) 2022 David Vernet <dvernet@meta.com>
  */
+#include <linux/bitmap.h>
+#include <linux/btf_ids.h>
+#include <linux/rhashtable.h>
+#include <linux/sched/clock.h>
+#include <linux/sched/isolation.h>
+#include <linux/suspend.h>
+#include <linux/sysrq.h>
+
+#include "../pelt.h"
+#include "internal.h"
+#include "cid.h"
+#include "arena.h"
+#include "idle.h"
 
 static DEFINE_RAW_SPINLOCK(scx_sched_lock);
 
diff --git a/kernel/sched/ext/idle.c b/kernel/sched/ext/idle.c
index 2077373d8da3..8e8c6201b7df 100644
--- a/kernel/sched/ext/idle.c
+++ b/kernel/sched/ext/idle.c
@@ -9,6 +9,9 @@
  * Copyright (c) 2022 David Vernet <dvernet@meta.com>
  * Copyright (c) 2024 Andrea Righi <arighi@nvidia.com>
  */
+#include "internal.h"
+#include "cid.h"
+#include "idle.h"
 
 /* Enable/disable built-in idle CPU selection policy */
 static DEFINE_STATIC_KEY_FALSE(scx_builtin_idle_enabled);
diff --git a/kernel/sched/ext/idle.h b/kernel/sched/ext/idle.h
index 8d169d3bbdf9..87a0e58f1eb7 100644
--- a/kernel/sched/ext/idle.h
+++ b/kernel/sched/ext/idle.h
@@ -10,7 +10,11 @@
 #ifndef _KERNEL_SCHED_EXT_IDLE_H
 #define _KERNEL_SCHED_EXT_IDLE_H
 
+#include <linux/btf_ids.h>
+
+struct cpumask;
 struct sched_ext_ops;
+struct task_struct;
 
 extern struct btf_id_set8 scx_kfunc_ids_idle;
 extern struct btf_id_set8 scx_kfunc_ids_select_cpu;
diff --git a/kernel/sched/ext/internal.h b/kernel/sched/ext/internal.h
index b04701190b23..1f5312b3b387 100644
--- a/kernel/sched/ext/internal.h
+++ b/kernel/sched/ext/internal.h
@@ -5,6 +5,12 @@
  * Copyright (c) 2025 Meta Platforms, Inc. and affiliates.
  * Copyright (c) 2025 Tejun Heo <tj@kernel.org>
  */
+#ifndef _KERNEL_SCHED_EXT_INTERNAL_H
+#define _KERNEL_SCHED_EXT_INTERNAL_H
+
+#include "../sched.h"
+#include "types.h"
+
 #define SCX_OP_IDX(op)		(offsetof(struct sched_ext_ops, op) / sizeof(void (*)(void)))
 #define SCX_MOFF_IDX(moff)	((moff) / sizeof(void (*)(void)))
 
@@ -1651,3 +1657,5 @@ static inline struct scx_sched *scx_prog_sched(const struct bpf_prog_aux *aux)
 	return rcu_dereference_all(scx_root);
 }
 #endif	/* CONFIG_EXT_SUB_SCHED */
+
+#endif /* _KERNEL_SCHED_EXT_INTERNAL_H */
diff --git a/kernel/sched/ext/types.h b/kernel/sched/ext/types.h
index 8b3527e21fca..bc74eafd43f1 100644
--- a/kernel/sched/ext/types.h
+++ b/kernel/sched/ext/types.h
@@ -8,6 +8,12 @@
 #ifndef _KERNEL_SCHED_EXT_TYPES_H
 #define _KERNEL_SCHED_EXT_TYPES_H
 
+#include <linux/types.h>
+#include <linux/jiffies.h>
+#include <linux/overflow.h>
+#include <linux/time64.h>
+#include <linux/sched/topology.h>
+
 enum scx_consts {
 	SCX_DSP_DFL_MAX_BATCH		= 32,
 	SCX_DSP_MAX_LOOPS		= 32,