diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index bed8fbb45f31..6b183521c616 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -30,6 +30,7 @@
 #include <linux/device.h>	/* for struct device */
 #include <linux/sched.h>	/* for completion */
 #include <linux/mutex.h>
+#include <linux/rtmutex.h>
 #include <linux/irqdomain.h>		/* for Host Notify IRQ */
 #include <linux/of.h>		/* for struct device_node */
 #include <linux/swab.h>		/* for swab16 */
diff --git a/kernel/fork.c b/kernel/fork.c
index 08d6c091ac7c..8fbe8bcd1e20 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -17,6 +17,7 @@
 #include <linux/sched/coredump.h>
 #include <linux/sched/user.h>
 #include <linux/sched/numa_balancing.h>
+#include <linux/rtmutex.h>
 #include <linux/init.h>
 #include <linux/unistd.h>
 #include <linux/module.h>
diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c
index 5ea0a8969ee2..f24582d4dad3 100644
--- a/kernel/locking/locktorture.c
+++ b/kernel/locking/locktorture.c
@@ -33,6 +33,7 @@
 #include <linux/interrupt.h>
 #include <linux/sched.h>
 #include <uapi/linux/sched/types.h>
+#include <linux/rtmutex.h>
 #include <linux/atomic.h>
 #include <linux/moduleparam.h>
 #include <linux/delay.h>
diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h
index b60f2b6caa14..ec62a05bfdb3 100644
--- a/kernel/rcu/tree.h
+++ b/kernel/rcu/tree.h
@@ -24,6 +24,7 @@
 
 #include <linux/cache.h>
 #include <linux/spinlock.h>
+#include <linux/rtmutex.h>
 #include <linux/threads.h>
 #include <linux/cpumask.h>
 #include <linux/seqlock.h>