diff --git a/doc/man/s3fs.1 b/doc/man/s3fs.1
index fec888c..e22247e 100644
--- a/doc/man/s3fs.1
+++ b/doc/man/s3fs.1
@@ -256,6 +256,10 @@ Customize TLS cipher suite list. Expects a colon separated list of cipher suite
 A list of available cipher suites, depending on your TLS engine, can be found on the CURL library documentation:
 https://curl.haxx.se/docs/ssl-ciphers.html
 .TP
+\fB\-o\fR instance_name
+The instance name of the current s3fs mountpoint.
+This name will be added to logging messages and user agent headers sent by s3fs.
+.TP
 \fB\-o\fR complement_stat (complement lack of file/directory mode)
 s3fs complements lack of information about file/directory mode if a file or a directory object does not have x-amz-meta-mode header.
 As default, s3fs does not complements stat information for a object, then the object will not be able to be allowed to list/modify.
diff --git a/src/common.h b/src/common.h
index 84d0747..d996c37 100644
--- a/src/common.h
+++ b/src/common.h
@@ -79,7 +79,7 @@ enum s3fs_log_level{
          if(foreground){ \
            fprintf(stdout, "%s%s:%s(%d): " fmt "%s\n", S3FS_LOG_LEVEL_STRING(level), __FILE__, __func__, __LINE__, __VA_ARGS__); \
          }else{ \
-           syslog(S3FS_LOG_LEVEL_TO_SYSLOG(level), "%s:%s(%d): " fmt "%s", __FILE__, __func__, __LINE__, __VA_ARGS__); \
+           syslog(S3FS_LOG_LEVEL_TO_SYSLOG(level), "%s%s:%s(%d): " fmt "%s", instance_name.c_str(), __FILE__, __func__, __LINE__, __VA_ARGS__); \
          } \
        }
 
@@ -88,7 +88,7 @@ enum s3fs_log_level{
          if(foreground){ \
            fprintf(stdout, "%s%s%s:%s(%d): " fmt "%s\n", S3FS_LOG_LEVEL_STRING(level), S3FS_LOG_NEST(nest), __FILE__, __func__, __LINE__, __VA_ARGS__); \
          }else{ \
-           syslog(S3FS_LOG_LEVEL_TO_SYSLOG(level), "%s" fmt "%s", S3FS_LOG_NEST(nest), __VA_ARGS__); \
+           syslog(S3FS_LOG_LEVEL_TO_SYSLOG(level), "%s%s" fmt "%s", instance_name.c_str(), S3FS_LOG_NEST(nest), __VA_ARGS__); \
          } \
        }
 
@@ -97,7 +97,7 @@ enum s3fs_log_level{
          fprintf(stderr, "s3fs: " fmt "%s\n", __VA_ARGS__); \
        }else{ \
          fprintf(stderr, "s3fs: " fmt "%s\n", __VA_ARGS__); \
-         syslog(S3FS_LOG_LEVEL_TO_SYSLOG(S3FS_LOG_CRIT), "s3fs: " fmt "%s", __VA_ARGS__); \
+         syslog(S3FS_LOG_LEVEL_TO_SYSLOG(S3FS_LOG_CRIT), "%ss3fs: " fmt "%s", instance_name.c_str(), __VA_ARGS__); \
        }
 
 // Special macro for init message
@@ -105,7 +105,7 @@ enum s3fs_log_level{
        if(foreground){ \
          fprintf(stdout, "%s%s%s:%s(%d): " fmt "%s\n", S3FS_LOG_LEVEL_STRING(S3FS_LOG_INFO), S3FS_LOG_NEST(0), __FILE__, __func__, __LINE__, __VA_ARGS__, ""); \
        }else{ \
-         syslog(S3FS_LOG_LEVEL_TO_SYSLOG(S3FS_LOG_INFO), "%s" fmt "%s", S3FS_LOG_NEST(0), __VA_ARGS__, ""); \
+         syslog(S3FS_LOG_LEVEL_TO_SYSLOG(S3FS_LOG_INFO), "%s%s" fmt "%s", instance_name.c_str(), S3FS_LOG_NEST(0), __VA_ARGS__, ""); \
        }
 
 // [NOTE]
@@ -168,6 +168,7 @@ extern std::string    bucket;
 extern std::string    mount_prefix;
 extern std::string    endpoint;
 extern std::string    cipher_suites;
+extern std::string    instance_name;
 extern s3fs_log_level debug_level;
 extern const char*    s3fs_log_nest[S3FS_LOG_NEST_MAX];
 
diff --git a/src/curl.cpp b/src/curl.cpp
index ebb7adf..5ea7af2 100644
--- a/src/curl.cpp
+++ b/src/curl.cpp
@@ -631,6 +631,7 @@ void S3fsCurl::InitUserAgent(void)
     S3fsCurl::userAgent += "; ";
     S3fsCurl::userAgent += s3fs_crypt_lib_name();
     S3fsCurl::userAgent += ")";
+    S3fsCurl::userAgent += instance_name;
   }
 }
 
diff --git a/src/s3fs.cpp b/src/s3fs.cpp
index aae4e89..53bdb5a 100644
--- a/src/s3fs.cpp
+++ b/src/s3fs.cpp
@@ -100,6 +100,7 @@ std::string host                  = "https://s3.amazonaws.com";
 std::string bucket                = "";
 std::string endpoint              = "us-east-1";
 std::string cipher_suites         = "";
+std::string instance_name         = "";
 s3fs_log_level debug_level        = S3FS_LOG_CRIT;
 const char*    s3fs_log_nest[S3FS_LOG_NEST_MAX] = {"", "  ", "    ", "      "};
 
@@ -4777,6 +4778,11 @@ static int my_fuse_opt_proc(void* data, const char* arg, int key, struct fuse_ar
       cipher_suites = strchr(arg, '=') + sizeof(char);
       return 0;
     }
+    if(0 == STR2NCMP(arg, "instance_name=")){
+      instance_name = strchr(arg, '=') + sizeof(char);
+      instance_name = "[" + instance_name + "]";
+      return 0;
+    }
     //
     // debug option for s3fs
     //
diff --git a/src/s3fs_util.cpp b/src/s3fs_util.cpp
index 3d05136..483514d 100644
--- a/src/s3fs_util.cpp
+++ b/src/s3fs_util.cpp
@@ -1240,6 +1240,9 @@ void show_help (void)
     "        can be found on the CURL library documentation:\n"
     "        https://curl.haxx.se/docs/ssl-ciphers.html\n"
     "\n"
+    "   instance_name - The instance name of the current s3fs mountpoint.\n"
+    "        This name will be added to logging messages and user agent headers sent by s3fs.\n"
+    "\n"
     "   complement_stat (complement lack of file/directory mode)\n"
     "        s3fs complements lack of information about file/directory mode\n"
     "        if a file or a directory object does not have x-amz-meta-mode\n"