Linked stack in C

stack.c

#include "stack.h"
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <assert.h>

void stackpush(Stack ** stack, int value)
{
        assert(stack != NULL);

        if (*stack == NULL)
        {
                *stack = (Stack *)malloc(sizeof(Stack));
                assert(*stack != NULL); /* TODO : allocation handling! */
                (*stack)->value = value;
                (*stack)->lower = NULL;
                return;
        }
        else
        {
                Stack *new_node = (Stack *)malloc(sizeof(Stack));
                assert(new_node != NULL); /* TODO : allocation handling! */
                new_node->lower = *stack;
                new_node->value = value;
                *stack = new_node;
                return;
        }
}

int stackpop(Stack ** stack)
{
        assert(stack != NULL); /* here it might be wise to do NULL handling */

        Stack *new_top = (*stack)->lower;
        int removed_value = (*stack)->value;

        free(*stack);

        *stack = new_top;
        return removed_value;
}

void stackdispose(Stack * stack)
{
        while(stack != NULL)
        	stackpop(&stack);
}

stack.h

typedef struct node_t
{
    int value;
    struct node_t * lower;
} Node;

typedef struct node_t Stack;

void stackpush(Stack**, int);
int stackpop(Stack**);
void stackdispose(Stack*);