diff --git a/arch/xtensa/core/thread.c b/arch/xtensa/core/thread.c
index eac97bc9f41..f48a9d8c10d 100644
--- a/arch/xtensa/core/thread.c
+++ b/arch/xtensa/core/thread.c
@@ -82,8 +82,7 @@ void _new_thread(char *pStack, size_t stackSize,
 		int prio, unsigned int options)
 {
 	/* Align stack end to maximum alignment requirement. */
-	char *stackEnd = (char *)ROUND_DOWN(pStack + stackSize,
-		(XCHAL_TOTAL_SA_ALIGN < 16 ? 16 : XCHAL_TOTAL_SA_ALIGN));
+	char *stackEnd = (char *)ROUND_DOWN(pStack + stackSize, 16);
 	/* k_thread is located at top of stack while frames are located at end
 	 * of it
 	 */
@@ -101,7 +100,6 @@ void _new_thread(char *pStack, size_t stackSize,
 #endif
 #if XCHAL_CP_NUM > 0
 	/* Coprocessor's stack is allocated just after the k_thread */
-	thread->arch.preempCoprocReg.cpStack = pStack + sizeof(struct k_thread);
 	cpSA = (uint32_t *)(thread->arch.preempCoprocReg.cpStack + XT_CP_ASA);
 	/* Coprocessor's save area alignment is at leat 16 bytes */
 	*cpSA = ROUND_UP(cpSA + 1,
diff --git a/arch/xtensa/include/kernel_arch_data.h b/arch/xtensa/include/kernel_arch_data.h
index 87d9539e7e8..4c2eb884ac9 100644
--- a/arch/xtensa/include/kernel_arch_data.h
+++ b/arch/xtensa/include/kernel_arch_data.h
@@ -103,19 +103,18 @@ typedef struct s_coopCoprocReg {
 } tCoopCoprocReg;
 
 /*
- * The following structure defines the set of 'volatile' x87 FPU/MMX/SSE
- * registers.  These registers need not be preserved by a called C function.
+ * The following structure defines the set of 'volatile' coprocessor
+ * registers. These registers need not be preserved by a called C function.
  * Given that they are not preserved across function calls, they must be
  * save/restored (along with s_coopCoprocReg) when a preemptive context switch
  * occurs.
  */
 typedef struct s_preempCoprocReg {
 	/*
-	 * This structure intentionally left blank, as for now coprocessor's
-	 * stack is positioned at top of the stack.
+	 * This structure reserves coprocessor control and save area memory.
 	 */
 #if XCHAL_CP_NUM > 0
-	char *cpStack;
+	char __aligned(4) cpStack[XT_CP_SIZE];
 #endif
 } tPreempCoprocReg;