diff --git a/mosquitto.c b/mosquitto.c
index bc209b1..ec8e4c4 100644
--- a/mosquitto.c
+++ b/mosquitto.c
@@ -887,6 +887,7 @@ static zend_object_value mosquitto_client_object_new(zend_class_entry *ce TSRMLS
 
 void php_mosquitto_handle_errno(int retval, int err TSRMLS_DC) {
 	const char *message;
+	int own_string = 0;
 
 	switch (retval) {
 		case MOSQ_ERR_SUCCESS:
@@ -894,6 +895,7 @@ void php_mosquitto_handle_errno(int retval, int err TSRMLS_DC) {
 
 		case MOSQ_ERR_ERRNO:
 			message = php_mosquitto_strerror_wrapper(errno);
+			own_string = 1;
 			break;
 
 		default:
@@ -902,6 +904,9 @@ void php_mosquitto_handle_errno(int retval, int err TSRMLS_DC) {
 	}
 
 	zend_throw_exception(mosquitto_ce_exception, (char *) message, 0 TSRMLS_CC);
+	if (own_string) {
+		efree((void *) message);
+	}
 }
 
 PHP_MOSQUITTO_API void php_mosquitto_connect_callback(struct mosquitto *mosq, void *obj, int rc)