diff --git a/lib/packet_datatypes.c b/lib/packet_datatypes.c
index a07a9f54..1b0abeeb 100644
--- a/lib/packet_datatypes.c
+++ b/lib/packet_datatypes.c
@@ -231,8 +231,6 @@ int packet__write_varint(struct mosquitto__packet *packet, int32_t word)
 	uint8_t byte;
 	int count = 0;
 
-	packet->payload = NULL;
-	packet->remaining_count = 0;
 	do{
 		byte = word % 128;
 		word = word / 128;
diff --git a/test/unit/Makefile b/test/unit/Makefile
index fba2ce32..611e2098 100644
--- a/test/unit/Makefile
+++ b/test/unit/Makefile
@@ -9,6 +9,7 @@ TEST_OBJS = test.o \
 			datatype_read.o \
 			datatype_write.o \
 			property_read.o \
+			property_write.o \
 			stubs.o \
 			util_topic_test.o \
 			utf8.o
diff --git a/test/unit/property_read.c b/test/unit/property_read.c
index 4a8fa75d..97a8182c 100644
--- a/test/unit/property_read.c
+++ b/test/unit/property_read.c
@@ -338,7 +338,7 @@ static void varint_prop_read_helper(
 	CU_ASSERT_PTR_NULL(properties);
 }
 
-void packet_helper_reason_string_user_property(void)
+static void packet_helper_reason_string_user_property(void)
 {
 	uint8_t payload[24] = {23,
 		PROP_REASON_STRING, 0, 6, 'r', 'e', 'a', 's', 'o', 'n',
diff --git a/test/unit/property_write.c b/test/unit/property_write.c
new file mode 100644
index 00000000..4fca1d5c
--- /dev/null
+++ b/test/unit/property_write.c
@@ -0,0 +1,508 @@
+#include <CUnit/CUnit.h>
+#include <CUnit/Basic.h>
+
+#include "mqtt_protocol.h"
+#include "property_mosq.h"
+#include "packet_mosq.h"
+
+static void byte_prop_write_helper(
+		int remaining_length,
+		int rc_expected,
+		int identifier,
+		uint8_t value_expected)
+{
+	struct mqtt5__property property;
+	struct mosquitto__packet packet;
+	struct mqtt5__property *properties;
+	int rc;
+
+	memset(&property, 0, sizeof(struct mqtt5__property));
+
+	property.identifier = identifier;
+	property.value.i8 = value_expected;
+
+	memset(&packet, 0, sizeof(struct mosquitto__packet));
+	packet.remaining_length = property__get_length_all(&property)+1;
+	packet.packet_length = packet.remaining_length+10;
+	packet.payload = calloc(packet.remaining_length+10, 1);
+
+	property__write_all(&packet, &property);
+	packet.pos = 0;
+
+	rc = property__read_all(&packet, &properties);
+
+	CU_ASSERT_EQUAL(rc, rc_expected);
+	CU_ASSERT_EQUAL(packet.pos, remaining_length);
+	if(properties){
+		CU_ASSERT_EQUAL(properties->identifier, identifier);
+		CU_ASSERT_EQUAL(properties->value.i8, value_expected);
+		CU_ASSERT_PTR_EQUAL(properties->next, NULL);
+		CU_ASSERT_EQUAL(property__get_length_all(properties), 2);
+		property__free_all(&properties);
+	}
+	CU_ASSERT_PTR_EQUAL(properties, NULL);
+}
+
+
+static void int32_prop_write_helper(
+		int remaining_length,
+		int rc_expected,
+		int identifier,
+		uint32_t value_expected)
+{
+	struct mqtt5__property property;
+	struct mosquitto__packet packet;
+	struct mqtt5__property *properties;
+	int rc;
+
+	memset(&property, 0, sizeof(struct mqtt5__property));
+
+	property.identifier = identifier;
+	property.value.i32 = value_expected;
+
+	memset(&packet, 0, sizeof(struct mosquitto__packet));
+	packet.remaining_length = property__get_length_all(&property)+1;
+	packet.packet_length = packet.remaining_length+10;
+	packet.payload = calloc(packet.remaining_length+10, 1);
+
+	property__write_all(&packet, &property);
+	packet.pos = 0;
+
+	rc = property__read_all(&packet, &properties);
+
+	CU_ASSERT_EQUAL(rc, rc_expected);
+	CU_ASSERT_EQUAL(packet.pos, remaining_length);
+	if(properties){
+		CU_ASSERT_EQUAL(properties->identifier, identifier);
+		CU_ASSERT_EQUAL(properties->value.i32, value_expected);
+		CU_ASSERT_PTR_EQUAL(properties->next, NULL);
+		CU_ASSERT_EQUAL(property__get_length_all(properties), 5);
+		property__free_all(&properties);
+	}
+	CU_ASSERT_PTR_EQUAL(properties, NULL);
+}
+
+
+static void int16_prop_write_helper(
+		int remaining_length,
+		int rc_expected,
+		int identifier,
+		uint16_t value_expected)
+{
+	struct mqtt5__property property;
+	struct mosquitto__packet packet;
+	struct mqtt5__property *properties;
+	int rc;
+
+	memset(&property, 0, sizeof(struct mqtt5__property));
+
+	property.identifier = identifier;
+	property.value.i16 = value_expected;
+
+	memset(&packet, 0, sizeof(struct mosquitto__packet));
+	packet.remaining_length = property__get_length_all(&property)+1;
+	packet.packet_length = packet.remaining_length+10;
+	packet.payload = calloc(packet.remaining_length+10, 1);
+
+	property__write_all(&packet, &property);
+	packet.pos = 0;
+
+	rc = property__read_all(&packet, &properties);
+
+	CU_ASSERT_EQUAL(rc, rc_expected);
+	CU_ASSERT_EQUAL(packet.pos, remaining_length);
+	if(properties){
+		CU_ASSERT_EQUAL(properties->identifier, identifier);
+		CU_ASSERT_EQUAL(properties->value.i16, value_expected);
+		CU_ASSERT_PTR_EQUAL(properties->next, NULL);
+		CU_ASSERT_EQUAL(property__get_length_all(properties), 3);
+		property__free_all(&properties);
+	}
+	CU_ASSERT_PTR_EQUAL(properties, NULL);
+}
+
+static void string_prop_write_helper(
+		int remaining_length,
+		int rc_expected,
+		int identifier,
+		const char *value_expected)
+{
+	struct mqtt5__property property;
+	struct mosquitto__packet packet;
+	struct mqtt5__property *properties;
+	int rc;
+
+	memset(&property, 0, sizeof(struct mqtt5__property));
+
+	property.identifier = identifier;
+	property.value.s.v = strdup(value_expected);
+	property.value.s.len = strlen(value_expected);
+
+	memset(&packet, 0, sizeof(struct mosquitto__packet));
+	packet.remaining_length = property__get_length_all(&property)+1;
+	packet.packet_length = packet.remaining_length+10;
+	packet.payload = calloc(packet.remaining_length+10, 1);
+
+	property__write_all(&packet, &property);
+	packet.pos = 0;
+
+	rc = property__read_all(&packet, &properties);
+
+	CU_ASSERT_EQUAL(rc, rc_expected);
+	CU_ASSERT_EQUAL(packet.pos, remaining_length);
+	if(properties){
+		CU_ASSERT_EQUAL(properties->identifier, identifier);
+		CU_ASSERT_EQUAL(properties->value.s.len, strlen(value_expected));
+		CU_ASSERT_STRING_EQUAL(properties->value.s.v, value_expected);
+		CU_ASSERT_PTR_EQUAL(properties->next, NULL);
+		CU_ASSERT_EQUAL(property__get_length_all(properties), 1+2+strlen(value_expected));
+		property__free_all(&properties);
+	}
+	CU_ASSERT_PTR_EQUAL(properties, NULL);
+	free(property.value.s.v);
+}
+
+
+static void binary_prop_write_helper(
+		int remaining_length,
+		int rc_expected,
+		int identifier,
+		const uint8_t *value_expected,
+		int len_expected)
+{
+	struct mqtt5__property property;
+	struct mosquitto__packet packet;
+	struct mqtt5__property *properties;
+	int rc;
+
+	memset(&property, 0, sizeof(struct mqtt5__property));
+
+	property.identifier = identifier;
+	property.value.bin.v = malloc(len_expected);
+	memcpy(property.value.bin.v, value_expected, len_expected);
+	property.value.bin.len = len_expected;
+
+	memset(&packet, 0, sizeof(struct mosquitto__packet));
+	packet.remaining_length = property__get_length_all(&property)+1;
+	packet.packet_length = packet.remaining_length+10;
+	packet.payload = calloc(packet.remaining_length+10, 1);
+
+	property__write_all(&packet, &property);
+	packet.pos = 0;
+
+	rc = property__read_all(&packet, &properties);
+
+	CU_ASSERT_EQUAL(rc, rc_expected);
+	CU_ASSERT_EQUAL(packet.pos, remaining_length);
+	if(properties){
+		CU_ASSERT_EQUAL(properties->identifier, identifier);
+		CU_ASSERT_EQUAL(properties->value.bin.len, len_expected);
+		CU_ASSERT_EQUAL(memcmp(properties->value.bin.v, value_expected, len_expected), 0);
+		CU_ASSERT_PTR_EQUAL(properties->next, NULL);
+		CU_ASSERT_EQUAL(property__get_length_all(properties), 1+2+len_expected);
+		property__free_all(&properties);
+	}
+	CU_ASSERT_PTR_EQUAL(properties, NULL);
+	free(property.value.bin.v);
+}
+
+static void string_pair_prop_write_helper(
+		int remaining_length,
+		int rc_expected,
+		int identifier,
+		const char *name_expected,
+		const char *value_expected,
+		bool expect_multiple)
+{
+	struct mqtt5__property property;
+	struct mosquitto__packet packet;
+	struct mqtt5__property *properties;
+	int rc;
+
+	memset(&property, 0, sizeof(struct mqtt5__property));
+
+	property.identifier = identifier;
+	property.value.s.v = strdup(value_expected);
+	property.value.s.len = strlen(value_expected);
+	property.name.v = strdup(name_expected);
+	property.name.len = strlen(name_expected);
+
+	memset(&packet, 0, sizeof(struct mosquitto__packet));
+	packet.remaining_length = property__get_length_all(&property)+1;
+	packet.packet_length = packet.remaining_length+10;
+	packet.payload = calloc(packet.remaining_length+10, 1);
+
+	property__write_all(&packet, &property);
+	packet.pos = 0;
+
+	rc = property__read_all(&packet, &properties);
+
+	CU_ASSERT_EQUAL(rc, rc_expected);
+	CU_ASSERT_EQUAL(packet.pos, remaining_length);
+	if(properties){
+		CU_ASSERT_EQUAL(properties->identifier, identifier);
+		CU_ASSERT_EQUAL(properties->name.len, strlen(name_expected));
+		CU_ASSERT_EQUAL(properties->value.s.len, strlen(value_expected));
+		CU_ASSERT_STRING_EQUAL(properties->name.v, name_expected);
+		CU_ASSERT_STRING_EQUAL(properties->value.s.v, value_expected);
+		if(expect_multiple){
+			CU_ASSERT_PTR_NOT_NULL(properties->next);
+		}else{
+			CU_ASSERT_PTR_NULL(properties->next);
+			CU_ASSERT_EQUAL(property__get_length_all(properties), 1+2+strlen(name_expected)+2+strlen(value_expected));
+		}
+		property__free_all(&properties);
+	}
+	CU_ASSERT_PTR_NULL(properties);
+	free(property.value.s.v);
+	free(property.name.v);
+}
+
+static void varint_prop_write_helper(
+		int remaining_length,
+		int rc_expected,
+		int identifier,
+		uint32_t value_expected)
+{
+	struct mqtt5__property property;
+	struct mosquitto__packet packet;
+	struct mqtt5__property *properties;
+	int rc;
+
+	memset(&property, 0, sizeof(struct mqtt5__property));
+
+	property.identifier = identifier;
+	property.value.varint = value_expected;
+
+	memset(&packet, 0, sizeof(struct mosquitto__packet));
+	packet.remaining_length = property__get_length_all(&property)+1;
+	packet.packet_length = packet.remaining_length+10;
+	packet.payload = calloc(packet.remaining_length+10, 1);
+
+	property__write_all(&packet, &property);
+	packet.pos = 0;
+
+	rc = property__read_all(&packet, &properties);
+
+	CU_ASSERT_EQUAL(rc, rc_expected);
+	if(properties){
+		CU_ASSERT_EQUAL(properties->identifier, identifier);
+		CU_ASSERT_EQUAL(properties->value.varint, value_expected);
+		CU_ASSERT_PTR_NULL(properties->next);
+		if(value_expected < 128){
+			CU_ASSERT_EQUAL(property__get_length_all(properties), 2);
+		}else if(value_expected < 16384){
+			CU_ASSERT_EQUAL(property__get_length_all(properties), 3);
+		}else if(value_expected < 2097152){
+			CU_ASSERT_EQUAL(property__get_length_all(properties), 4);
+		}else if(value_expected < 268435456){
+			CU_ASSERT_EQUAL(property__get_length_all(properties), 5);
+		}else{
+			CU_FAIL("Incorrect varint value.");
+		}
+		property__free_all(&properties);
+	}
+	CU_ASSERT_PTR_NULL(properties);
+}
+
+/* ========================================================================
+ * SINGLE PROPERTIES
+ * ======================================================================== */
+
+static void TEST_single_payload_format_indicator(void)
+{
+	byte_prop_write_helper(3, MOSQ_ERR_SUCCESS, PROP_PAYLOAD_FORMAT_INDICATOR, 1);
+}
+
+static void TEST_single_request_problem_information(void)
+{
+	byte_prop_write_helper(3, MOSQ_ERR_SUCCESS, PROP_REQUEST_PROBLEM_INFO, 1);
+}
+
+static void TEST_single_request_response_information(void)
+{
+	byte_prop_write_helper(3, MOSQ_ERR_SUCCESS, PROP_REQUEST_RESPONSE_INFO, 1);
+}
+
+static void TEST_single_maximum_qos(void)
+{
+	byte_prop_write_helper(3, MOSQ_ERR_SUCCESS, PROP_MAXIMUM_QOS, 1);
+}
+
+static void TEST_single_retain_available(void)
+{
+	byte_prop_write_helper(3, MOSQ_ERR_SUCCESS, PROP_RETAIN_AVAILABLE, 1);
+}
+
+static void TEST_single_wildcard_subscription_available(void)
+{
+	byte_prop_write_helper(3, MOSQ_ERR_SUCCESS, PROP_WILDCARD_SUB_AVAILABLE, 0);
+}
+
+static void TEST_single_subscription_identifier_available(void)
+{
+	byte_prop_write_helper(3, MOSQ_ERR_SUCCESS, PROP_SUBSCRIPTION_ID_AVAILABLE, 0);
+}
+
+static void TEST_single_shared_subscription_available(void)
+{
+	byte_prop_write_helper(3, MOSQ_ERR_SUCCESS, PROP_SHARED_SUB_AVAILABLE, 1);
+}
+
+static void TEST_single_message_expiry_interval(void)
+{
+	int32_prop_write_helper(6, MOSQ_ERR_SUCCESS, PROP_MESSAGE_EXPIRY_INTERVAL, 0x12233445);
+}
+
+static void TEST_single_session_expiry_interval(void)
+{
+	int32_prop_write_helper(6, MOSQ_ERR_SUCCESS, PROP_SESSION_EXPIRY_INTERVAL, 0x45342312);
+}
+
+static void TEST_single_will_delay_interval(void)
+{
+	int32_prop_write_helper(6, MOSQ_ERR_SUCCESS, PROP_WILL_DELAY_INTERVAL, 0x45342312);
+}
+
+static void TEST_single_maximum_packet_size(void)
+{
+	int32_prop_write_helper(6, MOSQ_ERR_SUCCESS, PROP_MAXIMUM_PACKET_SIZE, 0x45342312);
+}
+
+static void TEST_single_server_keep_alive(void)
+{
+	int16_prop_write_helper(4, MOSQ_ERR_SUCCESS, PROP_SERVER_KEEP_ALIVE, 0x4534);
+}
+
+static void TEST_single_receive_maximum(void)
+{
+	int16_prop_write_helper(4, MOSQ_ERR_SUCCESS, PROP_RECEIVE_MAXIMUM, 0x6842);
+}
+
+static void TEST_single_topic_alias_maximum(void)
+{
+	int16_prop_write_helper(4, MOSQ_ERR_SUCCESS, PROP_TOPIC_ALIAS_MAXIMUM, 0x6842);
+}
+
+static void TEST_single_topic_alias(void)
+{
+	int16_prop_write_helper(4, MOSQ_ERR_SUCCESS, PROP_TOPIC_ALIAS, 0x6842);
+}
+
+static void TEST_single_content_type(void)
+{
+	string_prop_write_helper(9, MOSQ_ERR_SUCCESS, PROP_CONTENT_TYPE, "hello");
+}
+
+static void TEST_single_response_topic(void)
+{
+	string_prop_write_helper(9, MOSQ_ERR_SUCCESS, PROP_RESPONSE_TOPIC, "hello");
+}
+
+static void TEST_single_assigned_client_identifier(void)
+{
+	string_prop_write_helper(9, MOSQ_ERR_SUCCESS, PROP_ASSIGNED_CLIENT_IDENTIFIER, "hello");
+}
+
+static void TEST_single_authentication_method(void)
+{
+	string_prop_write_helper(9, MOSQ_ERR_SUCCESS, PROP_AUTHENTICATION_METHOD, "hello");
+}
+
+static void TEST_single_response_information(void)
+{
+	string_prop_write_helper(9, MOSQ_ERR_SUCCESS, PROP_RESPONSE_INFO, "hello");
+}
+
+static void TEST_single_server_reference(void)
+{
+	string_prop_write_helper(9, MOSQ_ERR_SUCCESS, PROP_SERVER_REFERENCE, "hello");
+}
+
+static void TEST_single_reason_string(void)
+{
+	string_prop_write_helper(9, MOSQ_ERR_SUCCESS, PROP_REASON_STRING, "hello");
+}
+
+static void TEST_single_correlation_data(void)
+{
+	uint8_t payload[5] = {1, 'e', 0, 'l', 9};
+
+	binary_prop_write_helper(9, MOSQ_ERR_SUCCESS, PROP_CORRELATION_DATA, payload, 5);
+}
+
+static void TEST_single_authentication_data(void)
+{
+	uint8_t payload[5] = {1, 'e', 0, 'l', 9};
+
+	binary_prop_write_helper(9, MOSQ_ERR_SUCCESS, PROP_AUTHENTICATION_DATA, payload, 5);
+}
+
+static void TEST_single_user_property(void)
+{
+	string_pair_prop_write_helper(10, MOSQ_ERR_SUCCESS, PROP_USER_PROPERTY, "za", "bc", false);
+}
+
+static void TEST_single_subscription_identifier(void)
+{
+	varint_prop_write_helper(3, MOSQ_ERR_SUCCESS, PROP_SUBSCRIPTION_IDENTIFIER, 0);
+	varint_prop_write_helper(3, MOSQ_ERR_SUCCESS, PROP_SUBSCRIPTION_IDENTIFIER, 127);
+	varint_prop_write_helper(4, MOSQ_ERR_SUCCESS, PROP_SUBSCRIPTION_IDENTIFIER, 128);
+	varint_prop_write_helper(4, MOSQ_ERR_SUCCESS, PROP_SUBSCRIPTION_IDENTIFIER, 16383);
+	varint_prop_write_helper(5, MOSQ_ERR_SUCCESS, PROP_SUBSCRIPTION_IDENTIFIER, 16384);
+	varint_prop_write_helper(5, MOSQ_ERR_SUCCESS, PROP_SUBSCRIPTION_IDENTIFIER, 2097151);
+	varint_prop_write_helper(6, MOSQ_ERR_SUCCESS, PROP_SUBSCRIPTION_IDENTIFIER, 2097152);
+	varint_prop_write_helper(6, MOSQ_ERR_SUCCESS, PROP_SUBSCRIPTION_IDENTIFIER, 268435455);
+}
+
+
+/* ========================================================================
+ * TEST SUITE SETUP
+ * ======================================================================== */
+
+int init_property_write_tests(void)
+{
+	CU_pSuite test_suite = NULL;
+
+	test_suite = CU_add_suite("Property write", NULL, NULL);
+	if(!test_suite){
+		printf("Error adding CUnit Property write test suite.\n");
+		return 1;
+	}
+
+	if(0
+			|| !CU_add_test(test_suite, "Single Payload Format Indicator", TEST_single_payload_format_indicator)
+			|| !CU_add_test(test_suite, "Single Request Problem Information", TEST_single_request_problem_information)
+			|| !CU_add_test(test_suite, "Single Request Response Information", TEST_single_request_response_information)
+			|| !CU_add_test(test_suite, "Single Maximum QoS", TEST_single_maximum_qos)
+			|| !CU_add_test(test_suite, "Single Retain Available", TEST_single_retain_available)
+			|| !CU_add_test(test_suite, "Single Wildcard Subscription Available", TEST_single_wildcard_subscription_available)
+			|| !CU_add_test(test_suite, "Single Subscription Identifier Available", TEST_single_subscription_identifier_available)
+			|| !CU_add_test(test_suite, "Single Shared Subscription Available", TEST_single_shared_subscription_available)
+			|| !CU_add_test(test_suite, "Single Message Expiry Interval", TEST_single_message_expiry_interval)
+			|| !CU_add_test(test_suite, "Single Session Expiry Interval", TEST_single_session_expiry_interval)
+			|| !CU_add_test(test_suite, "Single Will Delay Interval", TEST_single_will_delay_interval)
+			|| !CU_add_test(test_suite, "Single Maximum Packet Size", TEST_single_maximum_packet_size)
+			|| !CU_add_test(test_suite, "Single Server Keep Alive", TEST_single_server_keep_alive)
+			|| !CU_add_test(test_suite, "Single Receive Maximum", TEST_single_receive_maximum)
+			|| !CU_add_test(test_suite, "Single Topic Alias Maximum", TEST_single_topic_alias_maximum)
+			|| !CU_add_test(test_suite, "Single Topic Alias", TEST_single_topic_alias)
+			|| !CU_add_test(test_suite, "Single Content Type", TEST_single_content_type)
+			|| !CU_add_test(test_suite, "Single Response Topic", TEST_single_response_topic)
+			|| !CU_add_test(test_suite, "Single Assigned Client Identifier", TEST_single_assigned_client_identifier)
+			|| !CU_add_test(test_suite, "Single Authentication Method", TEST_single_authentication_method)
+			|| !CU_add_test(test_suite, "Single Response Information", TEST_single_response_information)
+			|| !CU_add_test(test_suite, "Single Server Reference", TEST_single_server_reference)
+			|| !CU_add_test(test_suite, "Single Reason String", TEST_single_reason_string)
+			|| !CU_add_test(test_suite, "Single Correlation Data", TEST_single_correlation_data)
+			|| !CU_add_test(test_suite, "Single Authentication Data", TEST_single_authentication_data)
+			|| !CU_add_test(test_suite, "Single User Property", TEST_single_user_property)
+			|| !CU_add_test(test_suite, "Single Subscription Identifier", TEST_single_subscription_identifier)
+			){
+
+		printf("Error adding Property read CUnit tests.\n");
+		return 1;
+	}
+
+	return 0;
+}
diff --git a/test/unit/test.c b/test/unit/test.c
index 1b920ed6..9e29f391 100644
--- a/test/unit/test.c
+++ b/test/unit/test.c
@@ -6,6 +6,7 @@
 int init_datatype_read_tests(void);
 int init_datatype_write_tests(void);
 int init_property_read_tests(void);
+int init_property_write_tests(void);
 int init_utf8_tests(void);
 int init_util_topic_tests(void);
 
@@ -22,6 +23,7 @@ int main(int argc, char *argv[])
 			|| init_datatype_read_tests()
 			|| init_datatype_write_tests()
 			|| init_property_read_tests()
+			|| init_property_write_tests()
 			|| init_util_topic_tests()
 			){