diff --git a/CMakeLists.txt b/CMakeLists.txt
index 0bac5ca..e2d3dbc 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -8,4 +8,5 @@ project(speq)
 target_sources(app PRIVATE
   src/main.c
   src/buffer.c
+  src/crc32.c
 )
diff --git a/src/crc32.c b/src/crc32.c
new file mode 100644
index 0000000..47953d1
--- /dev/null
+++ b/src/crc32.c
@@ -0,0 +1,95 @@
+/*
+ * Copyright (c) 2024 Space Cubics, LLC.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+#include <zephyr/ztest.h>
+#include <csp/csp.h>
+#include <csp/csp_crc32.h>
+#include <csp/csp_id.h>
+#include <endian.h>
+
+struct crc_fixture {
+	csp_packet_t *buf;
+};
+
+static struct crc_fixture crc_fixture;
+
+static void *setup(void)
+{
+	csp_init();
+
+	return &crc_fixture;
+}
+
+static void before(void *data)
+{
+	struct crc_fixture *fixture = data;
+
+	fixture->buf = csp_buffer_get(0);
+	zassert_true(fixture->buf != NULL, NULL);
+}
+
+static void after(void *data)
+{
+	struct crc_fixture *fixture = data;
+
+	csp_buffer_free(fixture->buf);
+}
+
+ZTEST_F(crc, test_crc_verify_without_crc)
+{
+	csp_packet_t *packet = fixture->buf;
+	int ret;
+
+	/* Check size error */
+	packet->length = 0;
+	ret = csp_crc32_verify(packet);
+	zassert_equal(ret, CSP_ERR_CRC32, "Expected error on size in csp_crc32_verify");
+
+	/* Check without crc */
+	memcpy(packet->data, "Hello", 5);
+	packet->length = 5;
+	ret = csp_crc32_verify(packet);
+	zassert_equal(ret, CSP_ERR_CRC32, "Expected error on crc in csp_crc32_verify");
+}
+
+ZTEST_F(crc, test_crc_without_header)
+{
+	csp_packet_t *packet = fixture->buf;
+	int ret;
+
+	memcpy(packet->data, "Hello", 5);
+	packet->length = 5;
+
+	/* Check without header */
+	csp_crc32_append(packet);
+	ret = csp_crc32_verify(packet);
+	zassert_equal(CSP_ERR_NONE, ret, "Error on csp_crc32_verify");
+}
+
+ZTEST_F(crc, test_crc_with_header)
+{
+	csp_packet_t *packet = fixture->buf;
+	uint32_t crc;
+	int ret;
+
+	memcpy(packet->data, "Hello", 5);
+	packet->length = 5;
+
+	/* Check with header.
+	 * This simulate CSP_21 define on csp_crc32_append().
+	 */
+	csp_id_prepend(packet);
+	crc = csp_crc32_memory(packet->frame_begin, packet->frame_length);
+	/* Convert to network byte order */
+	crc = htobe32(crc);
+	/* Copy checksum to packet */
+	memcpy(&packet->data[packet->length], &crc, sizeof(crc));
+	packet->length += sizeof(crc);
+
+	ret = csp_crc32_verify(packet);
+	zassert_equal(CSP_ERR_NONE, ret, "Error on csp_crc32_verify");
+}
+
+ZTEST_SUITE(crc, NULL, setup, before, after, NULL);