diff --git a/libs/esl/src/esl_oop.cpp b/libs/esl/src/esl_oop.cpp
index f34125a210..c7895b38aa 100644
--- a/libs/esl/src/esl_oop.cpp
+++ b/libs/esl/src/esl_oop.cpp
@@ -69,7 +69,8 @@ ESLevent *ESLconnection::api(const char *cmd, const char *arg)
 	assert(cmd_buf);
 
 	snprintf(cmd_buf, len, "api %s %s", cmd, arg ? arg : "");
-	*(cmd_buf + len) = '\0';
+	*(cmd_buf + (len + 1)) = '\0';
+
 
 	if (esl_send_recv(&handle, cmd_buf) == ESL_SUCCESS) {
 		esl_event_t *event;