diff --git a/core.c b/core.c
index 02d86cd..0f7fb2f 100644
--- a/core.c
+++ b/core.c
@@ -16,6 +16,7 @@
 #include "libmctp-alloc.h"
 #include "libmctp-log.h"
 #include "libmctp-cmds.h"
+#include "range.h"
 
 /* Internal data structures */
 
@@ -214,7 +215,7 @@
 
 		/* @todo: finer-grained allocation */
 		if (!ctx->buf_alloc_size) {
-			new_alloc_size = 4096;
+			new_alloc_size = MAX(len, 4096UL);
 		} else {
 			new_alloc_size = ctx->buf_alloc_size * 2;
 		}
diff --git a/tests/test_astlpc.c b/tests/test_astlpc.c
index 4baafb9..693ce60 100644
--- a/tests/test_astlpc.c
+++ b/tests/test_astlpc.c
@@ -26,6 +26,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/random.h>
 
 #ifndef ARRAY_SIZE
 #define ARRAY_SIZE(a) (sizeof(a) / sizeof(a[0]))
@@ -1070,6 +1071,64 @@
 	free(lpc_mem);
 }
 
+static void astlpc_test_send_large_packet(void)
+{
+	struct astlpc_endpoint *bmc, *host;
+	struct astlpc_test ctx;
+	uint8_t kcs[2] = { 0 };
+	void *lpc_mem;
+	int rc;
+
+	host = &ctx.host;
+	bmc = &ctx.bmc;
+
+	/* Test harness initialisation */
+	lpc_mem = calloc(1, 1 * 1024 * 1024);
+	assert(lpc_mem);
+
+	/* BMC initialisation */
+	rc = endpoint_init(bmc, 8, MCTP_BINDING_ASTLPC_MODE_BMC, 8192, &kcs,
+			   lpc_mem);
+	assert(!rc);
+
+	/* Host initialisation */
+	rc = endpoint_init(host, 9, MCTP_BINDING_ASTLPC_MODE_HOST, 8192, &kcs,
+			   lpc_mem);
+	assert(!rc);
+
+	ctx.count = 0;
+	mctp_set_rx_all(bmc->mctp, rx_message, &ctx);
+
+	rc = mctp_astlpc_poll(bmc->astlpc);
+	assert(rc == 0);
+
+	rc = mctp_astlpc_poll(host->astlpc);
+	assert(rc == 0);
+
+	ctx.msg = malloc(2 * MCTP_BODY_SIZE(8192));
+	assert(ctx.msg);
+
+	memset(ctx.msg, 0x5a, 2 * MCTP_BODY_SIZE(8192));
+
+	rc = mctp_message_tx(host->mctp, 8, ctx.msg, 2 * MCTP_BODY_SIZE(8192));
+	assert(rc == 0);
+	rc = mctp_astlpc_poll(bmc->astlpc);
+	assert(rc == 0);
+	rc = mctp_astlpc_poll(host->astlpc);
+	assert(rc == 0);
+	rc = mctp_astlpc_poll(bmc->astlpc);
+	assert(rc == 0);
+	rc = mctp_astlpc_poll(host->astlpc);
+	assert(rc == 0);
+
+	assert(ctx.count == 1);
+
+	free(ctx.msg);
+	endpoint_destroy(host);
+	endpoint_destroy(bmc);
+	free(lpc_mem);
+}
+
 /* clang-format off */
 #define TEST_CASE(test) { #test, test }
 static const struct {
@@ -1109,6 +1168,7 @@
 	TEST_CASE(astlpc_test_buffers_bad_host_init),
 	TEST_CASE(astlpc_test_negotiate_increased_mtu),
 	TEST_CASE(astlpc_test_negotiate_mtu_low_high),
+	TEST_CASE(astlpc_test_send_large_packet),
 };
 /* clang-format on */