--- a/lib/core/config.c
+++ b/lib/core/config.c
@@ -1,3 +1,4 @@
+
 /*
  * Copyright (c) 2014-2016 DeNA Co., Ltd.
  *
@@ -37,7 +38,9 @@ static h2o_hostconf_t *create_hostconf(h
     hostconf->http2.push_preload = 1; /* enabled by default */
     h2o_config_init_pathconf(&hostconf->fallback_path, globalconf, NULL, globalconf->mimemap);
     hostconf->mimemap = globalconf->mimemap;
-    h2o_mem_addref_shared(hostconf->mimemap);
+    if (hostconf->mimemap) {
+      h2o_mem_addref_shared(hostconf->mimemap);
+    }
     return hostconf;
 }
 
@@ -54,7 +57,9 @@ static void destroy_hostconf(h2o_hostcon
     }
     free(hostconf->paths.entries);
     h2o_config_dispose_pathconf(&hostconf->fallback_path);
-    h2o_mem_release_shared(hostconf->mimemap);
+    if (hostconf->mimemap) {
+      h2o_mem_release_shared(hostconf->mimemap);
+    }
 
     free(hostconf);
 }
@@ -136,8 +141,10 @@ void h2o_config_init_pathconf(h2o_pathco
     h2o_chunked_register(pathconf);
     if (path != NULL)
         pathconf->path = h2o_strdup(NULL, path, SIZE_MAX);
-    h2o_mem_addref_shared(mimemap);
-    pathconf->mimemap = mimemap;
+    if (mimemap) {
+      h2o_mem_addref_shared(mimemap);
+      pathconf->mimemap = mimemap;
+    }
     pathconf->error_log.emit_request_errors = 1;
 }
 
@@ -190,7 +197,7 @@ void h2o_config_init(h2o_globalconf_t *c
     config->http2.latency_optimization.max_additional_delay = 10;
     config->http2.latency_optimization.max_cwnd = 65535;
     config->http2.callbacks = H2O_HTTP2_CALLBACKS;
-    config->mimemap = h2o_mimemap_create();
+    // config->mimemap = h2o_mimemap_create();
 
     h2o_configurator__init_core(config);
 }
@@ -279,7 +286,9 @@ void h2o_config_dispose(h2o_globalconf_t
     }
     free(config->hosts);
 
-    h2o_mem_release_shared(config->mimemap);
+    if (config->mimemap) {
+      h2o_mem_release_shared(config->mimemap);
+    }
     h2o_configurator__dispose_configurators(config);
 }
 
--- a/lib/core/request.c
+++ b/lib/core/request.c
@@ -486,7 +486,7 @@ void h2o_req_fill_mime_attributes(h2o_re
     ssize_t content_type_index;
     h2o_mimemap_type_t *mime;
 
-    if (req->res.mime_attr != NULL)
+    if (req->res.mime_attr != NULL || req->pathconf->mimemap == NULL)
         return;
 
     if ((content_type_index = h2o_find_header(&req->res.headers, H2O_TOKEN_CONTENT_TYPE, -1)) != -1 &&