diff --git a/src/filesink.cpp b/src/filesink.cpp
index 82bc4f9..f7d3fa0 100644
--- a/src/filesink.cpp
+++ b/src/filesink.cpp
@@ -60,10 +60,12 @@ namespace g3 {
       auto now_formatted = g3::localtime_formatted(now, {internal::date_formatted + " " + internal::time_formatted});
 
       std::string file_name = createLogFileName(_log_prefix_backup);
-      std::string prospect_log = directory + file_name;
+      std::string prospect_log = directory + file_name;     
+
       std::unique_ptr<std::ofstream> log_stream = createLogFile(prospect_log);
       if (nullptr == log_stream) {
-         filestream() << "\n" << now_formatted << " Unable to change log file. Illegal filename or busy? Unsuccessful log name was: " << prospect_log;
+         filestream() << "\n" << now_formatted << " Unable to change log file."
+            << " Illegal filename or busy? Unsuccessful log name was: " << prospect_log;
          return {}; // no success
       }
 
diff --git a/src/filesinkhelper.ipp b/src/filesinkhelper.ipp
index c34d49f..e6e3061 100644
--- a/src/filesinkhelper.ipp
+++ b/src/filesinkhelper.ipp
@@ -24,7 +24,7 @@ namespace g3 {
 
       // check for filename validity -  filename should not be part of PATH
       bool isValidFilename(const std::string &prefix_filename) {
-         std::string illegal_characters("/,|<>:#$%{}()[]\'\"^!?+* ");
+         std::string illegal_characters("/,|<>:#$%{}[]\'\"^!?+* ");
          size_t pos = prefix_filename.find_first_of(illegal_characters, 0);
          if (pos != std::string::npos) {
             std::cerr << "Illegal character [" << prefix_filename.at(pos) << "] in logname prefix: " << "[" << prefix_filename << "]" << std::endl;
diff --git a/test_unit/test_filechange.cpp b/test_unit/test_filechange.cpp
index 17f4a58..a7df85c 100644
--- a/test_unit/test_filechange.cpp
+++ b/test_unit/test_filechange.cpp
@@ -2,7 +2,7 @@
  * 2012 by KjellKod.cc. This is PUBLIC DOMAIN to use at your own risk and comes
  * with no warranties. This code is yours to share, use and modify with no
  * strings attached and no restrictions or obligations.
- * 
+ *
  * For more information see g3log/LICENSE or refer refer to http://unlicense.org
  * ============================================================================*/
 
@@ -25,112 +25,124 @@ using namespace testing_helpers;
 
 
 namespace { // anonymous
-  const char* name_path_1 = "./some_fake_DirectoryOrName_1_";
-  g3::LogWorker* g_logger_ptr = nullptr;
-  g3::SinkHandle<g3::FileSink>* g_filesink_handler = nullptr;
-  LogFileCleaner* g_cleaner_ptr = nullptr;
+   const char* name_path_1 = "./(some_fake_DirectoryOrName_1_)";
+   g3::LogWorker* g_logger_ptr = nullptr;
+   g3::SinkHandle<g3::FileSink>* g_filesink_handler = nullptr;
+   LogFileCleaner* g_cleaner_ptr = nullptr;
 
-  std::string setLogNameAndAddCount(std::string new_file_to_create) {
-    static std::mutex m;
-    static int count;
-    std::string add_count;
-    std::lock_guard<std::mutex> lock(m);
-    {
-      add_count = std::to_string(++count) + "_";
-      auto future_new_log = g_filesink_handler->call(&g3::FileSink::changeLogFile, new_file_to_create + add_count);
+   std::string setLogNameAndAddCount(std::string new_file_to_create) {
+      static std::mutex m;
+      static int count;
+      std::string add_count;
+      std::lock_guard<std::mutex> lock(m);
+      {
+         add_count = std::to_string(++count) + "_";
+         auto future_new_log = g_filesink_handler->call(&g3::FileSink::changeLogFile, new_file_to_create + add_count);
+         auto new_log = future_new_log.get();
+         if (!new_log.empty()) {
+            g_cleaner_ptr->addLogToClean(new_log);
+         } else {
+          std::cout << "\nFailed to set filename: " << new_file_to_create << std::endl;
+         }
+         return new_log;
+      }
+      return add_count;
+   }
+
+   std::string setLogName(std::string new_file_to_create) {
+      auto future_new_log = g_filesink_handler->call(&g3::FileSink::changeLogFile, new_file_to_create);
       auto new_log = future_new_log.get();
       if (!new_log.empty()) g_cleaner_ptr->addLogToClean(new_log);
       return new_log;
-    }
-    return add_count;
-  }
+   }
 
-  std::string setLogName(std::string new_file_to_create) {
-    auto future_new_log = g_filesink_handler->call(&g3::FileSink::changeLogFile, new_file_to_create);
-    auto new_log = future_new_log.get();
-    if (!new_log.empty()) g_cleaner_ptr->addLogToClean(new_log);
-    return new_log;
-  }
-
-  std::string getLogName() {
-    return g_filesink_handler->call(&g3::FileSink::fileName).get();
-  }
+   std::string getLogName() {
+      return g_filesink_handler->call(&g3::FileSink::fileName).get();
+   }
 
 } // anonymous
 
 TEST(TestOf_GetFileName, Expecting_ValidLogFile) {
 
-  LOG(INFO) << "test_filechange, Retrieving file name: ";
-  ASSERT_NE(g_logger_ptr, nullptr);
-  ASSERT_FALSE(getLogName().empty());
+   LOG(INFO) << "test_filechange, Retrieving file name: ";
+   ASSERT_NE(g_logger_ptr, nullptr);
+   ASSERT_FALSE(getLogName().empty());
 }
 
 TEST(TestOf_ChangingLogFile, Expecting_NewLogFileUsed) {
-  auto old_log = getLogName();
-  std::string name = setLogNameAndAddCount(name_path_1);
-  auto new_log = setLogName(name);
-  ASSERT_NE(old_log, new_log);
+   auto old_log = getLogName();
+   std::string name = setLogNameAndAddCount(name_path_1);
+   auto new_log = setLogName(name);
+   ASSERT_NE(old_log, new_log);
 }
 
 TEST(TestOf_ManyThreadsChangingLogFileName, Expecting_EqualNumberLogsCreated) {
-  auto old_log = g_filesink_handler->call(&g3::FileSink::fileName).get();
-  if (!old_log.empty()) g_cleaner_ptr->addLogToClean(old_log);
+   auto old_log = g_filesink_handler->call(&g3::FileSink::fileName).get();
+   if (!old_log.empty()) g_cleaner_ptr->addLogToClean(old_log);
 
-  LOG(INFO) << "SoManyThreadsAllDoingChangeFileName";
-  std::vector<std::thread> threads;
-  auto max = 2;
-  auto size = g_cleaner_ptr->size();
-  for (auto count = 0; count < max; ++count) {
-    std::string drive = ((count % 2) == 0) ? "./_threadEven_" : "./_threaOdd_";
-    threads.push_back(std::thread(setLogNameAndAddCount, drive));
-  }
-  for (auto& thread : threads)
-    thread.join();
+   LOG(INFO) << "SoManyThreadsAllDoingChangeFileName";
+   std::vector<std::thread> threads;
+   auto max = 2;
+   auto size = g_cleaner_ptr->size();
+   for (auto count = 0; count < max; ++count) {
+      std::string drive = ((count % 2) == 0) ? "./_threadEven_" : "./_threaOdd_";
+      threads.push_back(std::thread(setLogNameAndAddCount, drive));
+   }
+   for (auto& thread : threads)
+      thread.join();
 
-  // check that all logs were created
-  ASSERT_EQ(size + max, g_cleaner_ptr->size());
+   // check that all logs were created
+   ASSERT_EQ(size + max, g_cleaner_ptr->size());
 }
 
 TEST(TestOf_IllegalLogFileName, Expecting_NoChangeToOriginalFileName) {
-  std::string original = getLogName();
-  auto perhaps_a_name = setLogName("XY:/"); // does not exist
-  ASSERT_TRUE(perhaps_a_name.empty());
-  std::string post_illegal = getLogName();
-  ASSERT_STREQ(original.c_str(), post_illegal.c_str());
+   std::string original = getLogName();
+   auto perhaps_a_name = setLogName("XY:/"); // does not exist
+   ASSERT_TRUE(perhaps_a_name.empty());
+   std::string post_illegal = getLogName();
+   ASSERT_STREQ(original.c_str(), post_illegal.c_str());
 }
 
 
-int main(int argc, char *argv[]) {
-  LogFileCleaner cleaner;
-  g_cleaner_ptr = &cleaner;
-  int return_value = 1;
-  std::stringstream cerrDump;
-  
-  std::string last_log_file;
-  {
-    
-    testing_helpers::ScopedOut scopedCerr(std::cerr, &cerrDump);
-
-    auto worker = g3::LogWorker::createLogWorker();
-    auto handle= worker->addDefaultLogger("ReplaceLogFile", name_path_1);
-    g_logger_ptr = worker.get(); 
-    g_filesink_handler = handle.get();
-    last_log_file = g_filesink_handler->call(&g3::FileSink::fileName).get();
-    cleaner.addLogToClean(last_log_file);
-
-
-    g3::initializeLogging(g_logger_ptr);
-    LOG(INFO) << "test_filechange demo*" << std::endl;
-    
-    testing::InitGoogleTest(&argc, argv);
-    return_value = RUN_ALL_TESTS();
-
-    last_log_file = g_filesink_handler->call(&g3::FileSink::fileName).get();
-    std::cout << "log file at: " << last_log_file << std::endl;
-    //g3::shutDownLogging();
-  }
-  std::cout << "FINISHED WITH THE TESTING" << std::endl;
-  // cleaning up
-  cleaner.addLogToClean(last_log_file);
-  return return_value;
+TEST(TestOf_LegalLogFileNam,  With_parenthesis) {
+   std::string original = getLogName();
+   auto perhaps_a_name = setLogName("(test)"); // does not exist
+   std::string post_legal = getLogName();
+   EXPECT_TRUE(std::string::npos != post_legal.find("(test)")) << "filename was: " << post_legal;
+}
+
+
+int main(int argc, char* argv[]) {
+   LogFileCleaner cleaner;
+   g_cleaner_ptr = &cleaner;
+   int return_value = 1;
+   std::stringstream cerrDump;
+
+   std::string last_log_file;
+   {
+
+      testing_helpers::ScopedOut scopedCerr(std::cerr, &cerrDump);
+
+      auto worker = g3::LogWorker::createLogWorker();
+      auto handle = worker->addDefaultLogger("(ReplaceLogFile)", name_path_1);
+      g_logger_ptr = worker.get();
+      g_filesink_handler = handle.get();
+      last_log_file = g_filesink_handler->call(&g3::FileSink::fileName).get();
+      cleaner.addLogToClean(last_log_file);
+
+
+      g3::initializeLogging(g_logger_ptr);
+      LOG(INFO) << "test_filechange demo*" << std::endl;
+
+      testing::InitGoogleTest(&argc, argv);
+      return_value = RUN_ALL_TESTS();
+
+      last_log_file = g_filesink_handler->call(&g3::FileSink::fileName).get();
+      std::cout << "log file at: " << last_log_file << std::endl;
+      g3::internal::shutDownLogging();
+   }
+   std::cout << "FINISHED WITH THE TESTING" << std::endl;
+   // cleaning up
+   //cleaner.addLogToClean(last_log_file);
+   return return_value;
 }