diff --git a/src/shrpx.cc b/src/shrpx.cc
index 71af4447..a914a656 100644
--- a/src/shrpx.cc
+++ b/src/shrpx.cc
@@ -1121,7 +1121,7 @@ void fill_default_config() {
     accessconf.format = parse_log_format(DEFAULT_ACCESSLOG_FORMAT);
 
     auto &errorconf = loggingconf.error;
-    errorconf.file = strcopy("/dev/stderr");
+    errorconf.file = "/dev/stderr";
   }
 
   loggingconf.syslog_facility = LOG_DAEMON;
@@ -1752,7 +1752,7 @@ Logging:
               Set path to write error  log.  To reopen file, send USR1
               signal  to nghttpx.   stderr will  be redirected  to the
               error log file unless --errorlog-syslog is used.
-              Default: )" << get_config()->logging.error.file.get() << R"(
+              Default: )" << get_config()->logging.error.file << R"(
   --errorlog-syslog
               Send  error log  to  syslog.  If  this  option is  used,
               --errorlog-file option is ignored.
diff --git a/src/shrpx_config.cc b/src/shrpx_config.cc
index c16a6132..2c092148 100644
--- a/src/shrpx_config.cc
+++ b/src/shrpx_config.cc
@@ -1622,7 +1622,7 @@ int parse_config(const char *opt, const char *optarg,
     return parse_duration(&mod_config()->http2.timeout.stream_write, opt,
                           optarg);
   case SHRPX_OPTID_ACCESSLOG_FILE:
-    mod_config()->logging.access.file = strcopy(optarg);
+    mod_config()->logging.access.file = optarg;
 
     return 0;
   case SHRPX_OPTID_ACCESSLOG_SYSLOG:
@@ -1634,7 +1634,7 @@ int parse_config(const char *opt, const char *optarg,
 
     return 0;
   case SHRPX_OPTID_ERRORLOG_FILE:
-    mod_config()->logging.error.file = strcopy(optarg);
+    mod_config()->logging.error.file = optarg;
 
     return 0;
   case SHRPX_OPTID_ERRORLOG_SYSLOG:
diff --git a/src/shrpx_config.h b/src/shrpx_config.h
index 93d55ade..04faed86 100644
--- a/src/shrpx_config.h
+++ b/src/shrpx_config.h
@@ -504,12 +504,12 @@ struct Http2Config {
 struct LoggingConfig {
   struct {
     std::vector<LogFragment> format;
-    std::unique_ptr<char[]> file;
+    ImmutableString file;
     // Send accesslog to syslog, ignoring accesslog_file.
     bool syslog;
   } access;
   struct {
-    std::unique_ptr<char[]> file;
+    ImmutableString file;
     // Send errorlog to syslog, ignoring errorlog_file.
     bool syslog;
   } error;
diff --git a/src/shrpx_log.cc b/src/shrpx_log.cc
index 261b02e5..ae699e8b 100644
--- a/src/shrpx_log.cc
+++ b/src/shrpx_log.cc
@@ -393,23 +393,23 @@ int reopen_log_files() {
   auto &accessconf = get_config()->logging.access;
   auto &errorconf = get_config()->logging.error;
 
-  if (!accessconf.syslog && accessconf.file) {
-    new_accesslog_fd = util::open_log_file(accessconf.file.get());
+  if (!accessconf.syslog && !accessconf.file.empty()) {
+    new_accesslog_fd = util::open_log_file(accessconf.file.c_str());
 
     if (new_accesslog_fd == -1) {
-      LOG(ERROR) << "Failed to open accesslog file " << accessconf.file.get();
+      LOG(ERROR) << "Failed to open accesslog file " << accessconf.file;
       res = -1;
     }
   }
 
-  if (!errorconf.syslog && errorconf.file) {
-    new_errorlog_fd = util::open_log_file(errorconf.file.get());
+  if (!errorconf.syslog && !errorconf.file.empty()) {
+    new_errorlog_fd = util::open_log_file(errorconf.file.c_str());
 
     if (new_errorlog_fd == -1) {
       if (lgconf->errorlog_fd != -1) {
-        LOG(ERROR) << "Failed to open errorlog file " << errorconf.file.get();
+        LOG(ERROR) << "Failed to open errorlog file " << errorconf.file;
       } else {
-        std::cerr << "Failed to open errorlog file " << errorconf.file.get()
+        std::cerr << "Failed to open errorlog file " << errorconf.file
                   << std::endl;
       }