diff --git a/src/nghttpd.cc b/src/nghttpd.cc
index ba41d132..58179aea 100644
--- a/src/nghttpd.cc
+++ b/src/nghttpd.cc
@@ -183,6 +183,8 @@ int main(int argc, char **argv) {
 
   Config config;
   bool color = false;
+  auto mime_types_file_set_manually = false;
+
   while (1) {
     static int flag = 0;
     static option long_options[] = {
@@ -335,6 +337,7 @@ int main(int argc, char **argv) {
         break;
       case 9:
         // mime-types-file option
+        mime_types_file_set_manually = true;
         config.mime_types_file = optarg;
         break;
       }
@@ -375,7 +378,13 @@ int main(int argc, char **argv) {
     config.htdocs = "./";
   }
 
-  config.mime_types = util::read_mime_types(config.mime_types_file.c_str());
+  if (util::read_mime_types(config.mime_types,
+                            config.mime_types_file.c_str()) != 0) {
+    if (mime_types_file_set_manually) {
+      std::cerr << "--mime-types-file: Could not open mime types file: "
+                << config.mime_types_file << std::endl;
+    }
+  }
 
   set_color_output(color || isatty(fileno(stdout)));
 
diff --git a/src/util.cc b/src/util.cc
index 756a3e16..0870b20e 100644
--- a/src/util.cc
+++ b/src/util.cc
@@ -1218,13 +1218,11 @@ uint64_t get_uint64(const uint8_t *data) {
   return n;
 }
 
-std::map<std::string, std::string> read_mime_types(const char *filename) {
-  std::map<std::string, std::string> res;
-
+int read_mime_types(std::map<std::string, std::string> &res,
+                    const char *filename) {
   std::ifstream infile(filename);
   if (!infile) {
-    std::cerr << "Could not open mime types file: " << filename << std::endl;
-    return res;
+    return -1;
   }
 
   auto delim_pred = [](char c) { return c == ' ' || c == '\t'; };
@@ -1252,7 +1250,7 @@ std::map<std::string, std::string> read_mime_types(const char *filename) {
     }
   }
 
-  return res;
+  return 0;
 }
 
 } // namespace util
diff --git a/src/util.h b/src/util.h
index c386cf52..60662926 100644
--- a/src/util.h
+++ b/src/util.h
@@ -707,7 +707,11 @@ uint32_t get_uint32(const uint8_t *data);
 // order and returns it in host byte order.
 uint64_t get_uint64(const uint8_t *data);
 
-std::map<std::string, std::string> read_mime_types(const char *filename);
+// Reads mime types file (see /etc/mime.types), and stores extension
+// -> MIME type map in |res|.  This function returns 0 if it succeeds,
+// or -1.
+int read_mime_types(std::map<std::string, std::string> &res,
+                    const char *filename);
 
 } // namespace util