diff --git a/drivers/qmimodem/devinfo.c b/drivers/qmimodem/devinfo.c
index 0d66c538..f5028657 100644
--- a/drivers/qmimodem/devinfo.c
+++ b/drivers/qmimodem/devinfo.c
@@ -129,6 +129,7 @@ static void get_ids_cb(struct qmi_result *result, void *user_data)
 	str = qmi_result_get_string(result, QMI_DMS_RESULT_ESN);
 	/* Telit qmi modems return a "0" string when ESN is not available. */
 	if (!str || strcmp(str, "0") == 0) {
+		qmi_free(str);
 		str = qmi_result_get_string(result, QMI_DMS_RESULT_IMEI);
 		if (!str) {
 			CALLBACK_WITH_FAILURE(cb, NULL, cbd->data);