diff --git a/sys/arm64/arm64/swtch.S b/sys/arm64/arm64/swtch.S
--- a/sys/arm64/arm64/swtch.S
+++ b/sys/arm64/arm64/swtch.S
@@ -148,9 +148,7 @@
 	mov	x21, x2
 
 #ifdef VFP
-	/* Load the pcb address */
-	mov	x1, x4
-	bl	vfp_save_state
+	bl	vfp_save_state_switch
 	mov	x0, x20
 #else
 	mov	x0, x1
diff --git a/sys/arm64/arm64/vfp.c b/sys/arm64/arm64/vfp.c
--- a/sys/arm64/arm64/vfp.c
+++ b/sys/arm64/arm64/vfp.c
@@ -216,6 +216,14 @@
 	vfp_save_state_common(curthread, pcb);
 }
 
+void
+vfp_save_state_switch(struct thread *td)
+{
+	KASSERT(td != NULL, ("NULL vfp thread"));
+
+	vfp_save_state_common(td, td->td_pcb);
+}
+
 /*
  * Update the VFP state for a forked process or new thread. The PCB will
  * have been copied from the old thread.
diff --git a/sys/arm64/include/vfp.h b/sys/arm64/include/vfp.h
--- a/sys/arm64/include/vfp.h
+++ b/sys/arm64/include/vfp.h
@@ -79,6 +79,7 @@
 void	vfp_restore_state(void);
 void	vfp_save_state(struct thread *, struct pcb *);
 void	vfp_save_state_savectx(struct pcb *);
+void	vfp_save_state_switch(struct thread *);
 
 struct fpu_kern_ctx;