diff --git a/easylogger/inc/elog.h b/easylogger/inc/elog.h
index 719f4fbdbcf1c4854c5eaf76bf22ddbeb888400e..91c075627e0906bf1b1ff5e15de76a337b200f6e 100755
--- a/easylogger/inc/elog.h
+++ b/easylogger/inc/elog.h
@@ -163,6 +163,7 @@ typedef struct {
     bool output_lock_enabled;
     bool output_is_locked_before_enable;
     bool output_is_locked_before_disable;
+    bool output_is_locked;
 
 #ifdef ELOG_COLOR_ENABLE
     bool text_color_enabled;
diff --git a/easylogger/src/elog.c b/easylogger/src/elog.c
index 4b8fd5ad147322360e99febe58879ba921103183..29c336298f49f2c15e9ba67616fafe51da561f32 100755
--- a/easylogger/src/elog.c
+++ b/easylogger/src/elog.c
@@ -367,7 +367,10 @@ void elog_set_filter_kw(const char *keyword) {
  */
 void elog_output_lock(void) {
     if (elog.output_lock_enabled) {
-        elog_port_output_lock();
+        if (0 == elog.output_is_locked) {
+            elog_port_output_lock();
+            elog.output_is_locked = 1;
+        }
         elog.output_is_locked_before_disable = true;
     } else {
         elog.output_is_locked_before_enable = true;
@@ -380,6 +383,7 @@ void elog_output_lock(void) {
 void elog_output_unlock(void) {
     if (elog.output_lock_enabled) {
         elog_port_output_unlock();
+        elog.output_is_locked = 0;
         elog.output_is_locked_before_disable = false;
     } else {
         elog.output_is_locked_before_enable = false;