diff --git a/examples/ucontext-cp.c b/examples/ucontext-cp.c
index 0b2a6b5339ff858079e5d17cc91031a660eb2dc8..ea0c934f64ff98f6fa2039085539a173c7efd00a 100644
--- a/examples/ucontext-cp.c
+++ b/examples/ucontext-cp.c
@@ -28,7 +28,7 @@
 
 typedef struct {
 	struct io_uring *ring;
-	unsigned char stack_buf[SIGSTKSZ];
+	unsigned char *stack_buf;
 	ucontext_t ctx_main, ctx_fnew;
 } async_context;
 
@@ -115,8 +115,13 @@ static int setup_context(async_context *pctx, struct io_uring *ring)
 		perror("getcontext");
 		return -1;
 	}
-	pctx->ctx_fnew.uc_stack.ss_sp = &pctx->stack_buf;
-	pctx->ctx_fnew.uc_stack.ss_size = sizeof(pctx->stack_buf);
+	pctx->stack_buf = malloc(SIGSTKSZ);
+	if (!pctx->stack_buf) {
+		perror("malloc");
+		return -1;
+	}
+	pctx->ctx_fnew.uc_stack.ss_sp = pctx->stack_buf;
+	pctx->ctx_fnew.uc_stack.ss_size = SIGSTKSZ;
 	pctx->ctx_fnew.uc_link = &pctx->ctx_main;
 
 	return 0;
@@ -174,6 +179,7 @@ static void copy_file_wrapper(arguments_bundle *pbundle)
 	free(iov.iov_base);
 	close(pbundle->infd);
 	close(pbundle->outfd);
+	free(pbundle->pctx->stack_buf);
 	free(pbundle->pctx);
 	free(pbundle);