diff --git a/arch/sh/src/common/up_createstack.c b/arch/sh/src/common/up_createstack.c
index 35651fe863e..37346b84b3a 100644
--- a/arch/sh/src/common/up_createstack.c
+++ b/arch/sh/src/common/up_createstack.c
@@ -94,7 +94,7 @@ int up_create_stack(_TCB *tcb, size_t stack_size)
 
    if (!tcb->stack_alloc_ptr)
      {
-       tcb->stack_alloc_ptr = (uint32_t*)kzmalloc(stack_size);
+       tcb->stack_alloc_ptr = (uint32_t*)kzalloc(stack_size);
      }
 
    if (tcb->stack_alloc_ptr)
diff --git a/arch/z16/src/common/up_createstack.c b/arch/z16/src/common/up_createstack.c
index a59c79c8455..1adcc78358d 100644
--- a/arch/z16/src/common/up_createstack.c
+++ b/arch/z16/src/common/up_createstack.c
@@ -95,7 +95,7 @@ int up_create_stack(_TCB *tcb, size_t stack_size)
 
    if (!tcb->stack_alloc_ptr)
      {
-       tcb->stack_alloc_ptr = (uint32_t*)kzmalloc(stack_size);
+       tcb->stack_alloc_ptr = (uint32_t*)kzalloc(stack_size);
      }
 
    if (tcb->stack_alloc_ptr)
diff --git a/arch/z80/src/common/up_createstack.c b/arch/z80/src/common/up_createstack.c
index c9da4cb9f2e..6ffaa272bf1 100644
--- a/arch/z80/src/common/up_createstack.c
+++ b/arch/z80/src/common/up_createstack.c
@@ -93,7 +93,7 @@ int up_create_stack(_TCB *tcb, size_t stack_size)
 
    if (!tcb->stack_alloc_ptr)
      {
-       tcb->stack_alloc_ptr = (uint32_t*)kzmalloc(stack_size);
+       tcb->stack_alloc_ptr = (uint32_t*)kzalloc(stack_size);
      }
 
    if (tcb->stack_alloc_ptr)