diff --git a/sys/arm/arm/vm_machdep.c b/sys/arm/arm/vm_machdep.c
index 9326546374c2..97b8b76cf79f 100644
--- a/sys/arm/arm/vm_machdep.c
+++ b/sys/arm/arm/vm_machdep.c
@@ -402,7 +402,8 @@ cpu_thread_alloc(struct thread *td)
 	 * the ARM EABI.
 	 */
 	td->td_frame = (struct trapframe *)STACKALIGN((u_int)td->td_kstack +
-	    USPACE_SVC_STACK_TOP - sizeof(struct pcb) - 1);
+	    USPACE_SVC_STACK_TOP - sizeof(struct pcb) -
+	    sizeof(struct trapframe));
 #ifdef __XSCALE__
 #ifndef CPU_XSCALE_CORE3
 	pmap_use_minicache(td->td_kstack, td->td_kstack_pages * PAGE_SIZE);