diff --git a/include/cxxopts.hpp b/include/cxxopts.hpp
index 1a50874..7b4e2f1 100644
--- a/include/cxxopts.hpp
+++ b/include/cxxopts.hpp
@@ -672,6 +672,16 @@ inline bool IsFalseText(const std::string &text)
   return false;
 }
 
+static inline bool valid_option_later_char(char c)
+{
+  return c!='=' && c!=',' && !std::isspace(c, std::locale::classic()) && !std::iscntrl(c, std::locale::classic());
+}
+
+static inline bool valid_option_first_char(char c)
+{
+  return c != '-' && valid_option_later_char(c);
+}
+
 inline OptionNames split_option_names(const std::string &text)
 {
   OptionNames split_names;
@@ -692,25 +702,27 @@ inline OptionNames split_option_names(const std::string &text)
     }
     token_start_pos = next_non_space_pos;
     auto next_delimiter_pos = text.find(',', token_start_pos);
-    if (next_delimiter_pos == token_start_pos) {
-      throw_or_mimic<exceptions::invalid_option_format>(text);
-    }
+
     if (next_delimiter_pos == npos) {
       next_delimiter_pos = length;
     }
+    else if (next_delimiter_pos == token_start_pos) {
+      throw_or_mimic<exceptions::invalid_option_format>(text);
+    }
+    else if(next_delimiter_pos == length-1) {
+      // delimter at the end. ex : "a,ab,"
+      throw_or_mimic<exceptions::invalid_option_format>(text);
+    }
     auto token_length = next_delimiter_pos - token_start_pos;
-    // validate the token itself matches the regex /([:alnum:][-_[:alnum:]]*/
     {
-      const char* option_name_valid_chars =
-        "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
-        "abcdefghijklmnopqrstuvwxyz"
-        "0123456789"
-        "_-.?";
-
-      if (!std::isalnum(text[token_start_pos], std::locale::classic()) ||
-          text.find_first_not_of(option_name_valid_chars, token_start_pos) < next_delimiter_pos) {
+      if(!valid_option_first_char(text[token_start_pos])){
         throw_or_mimic<exceptions::invalid_option_format>(text);
       }
+      for(size_t i=token_start_pos+1; i<next_delimiter_pos; ++i){
+        if(!valid_option_later_char(text[i])) {
+          throw_or_mimic<exceptions::invalid_option_format>(text);
+        }
+      }
     }
     split_names.emplace_back(text.substr(token_start_pos, token_length));
     token_start_pos = next_delimiter_pos + 1;
@@ -726,11 +738,11 @@ inline ArguDesc ParseArgument(const char *arg, bool &matched)
   if (strncmp(pdata, "--", 2) == 0)
   {
     pdata += 2;
-    if (isalnum(*pdata, std::locale::classic()))
+    if (valid_option_first_char(*pdata))
     {
       argu_desc.arg_name.push_back(*pdata);
       pdata += 1;
-      while (isalnum(*pdata, std::locale::classic()) || *pdata == '-' || *pdata == '_' || *pdata == '.')
+      while (valid_option_later_char(*pdata))
       {
         argu_desc.arg_name.push_back(*pdata);
         pdata += 1;
@@ -757,7 +769,7 @@ inline ArguDesc ParseArgument(const char *arg, bool &matched)
   else if (strncmp(pdata, "-", 1) == 0)
   {
     pdata += 1;
-    if(isalnum(*pdata, std::locale::classic())) {
+    if(valid_option_first_char(*pdata)) {
       // If we have '=' right after first alnum, its a match.
       if(*(pdata+1) == '=') {
         argu_desc.arg_name.push_back(*pdata);
@@ -777,6 +789,13 @@ inline ArguDesc ParseArgument(const char *arg, bool &matched)
 #else  // CXXOPTS_NO_REGEX
 
 namespace {
+
+#define CXXOPTS_RE_NAME_START "[^-=,[:space:][:cntrl:]]"
+#define CXXOPTS_RE_NAME_CHAR "[^=,[:space:][:cntrl:]]"
+#define CXXOPTS_RE_NAME CXXOPTS_RE_NAME_START CXXOPTS_RE_NAME_CHAR "*"
+#define CXXOPTS_RE_LONG_NAME CXXOPTS_RE_NAME_START CXXOPTS_RE_NAME_CHAR "+"
+#define CXXOPTS_RE_SHORT_NAME CXXOPTS_RE_NAME_START
+
 CXXOPTS_LINKONCE
 const char* const integer_pattern =
   "(-)?(0x)?([0-9a-zA-Z]+)|((0x)?0)";
@@ -788,12 +807,12 @@ const char* const falsy_pattern =
   "(f|F)(alse)?|0";
 CXXOPTS_LINKONCE
 const char* const option_pattern =
-  "--([[:alnum:]][-_[:alnum:]\\.]+)(=(.*))?|-([[:alnum:]])((=(.*))|(.*))";
-// <-------Long Option--------------------> <-----Short Option------->
+  "--(" CXXOPTS_RE_LONG_NAME ")(=(.*))?|-(" CXXOPTS_RE_SHORT_NAME ")((=(.*))|(.*))";
+// <-------Long Option--------------->  <-------------Short Option--------------->
 // Groups :
-//   <---------1------------------><--2-->   <--4--------><-----5------>
-//                                   <-3>                  <--6--> <-8>
-//                                                           <-7>
+//   <---------1--------------><--2-->   <-----------4-------------><-----5------>
+//                               <-3>                                <--6--> <-8>
+//                                                                         <-7>
 const int LONG_NAME_IDX=1;
 const int LONG_MATCH_IDX=2;
 const int LONG_MATCH_VALUE_IDX=3;
@@ -804,10 +823,16 @@ const int SHORT_GROUPING_IDX=8;
 
 CXXOPTS_LINKONCE
 const char* const option_specifier_pattern =
-  "([[:alnum:]][-_[:alnum:]\\.]*)(,[ ]*[[:alnum:]][-_[:alnum:]]*)*";
+  "(" CXXOPTS_RE_NAME ")(,[ ]*" CXXOPTS_RE_NAME ")*";
 CXXOPTS_LINKONCE
 const char* const option_specifier_separator_pattern = ", *";
 
+#undef CXXOPTS_RE_NAME_START
+#undef CXXOPTS_RE_NAME_CHAR
+#undef CXXOPTS_RE_NAME
+#undef CXXOPTS_RE_LONG_NAME
+#undef CXXOPTS_RE_SHORT_NAME
+
 } // namespace
 
 inline IntegerDesc SplitInteger(const std::string &text)
diff --git a/test/options.cpp b/test/options.cpp
index 7ef5aca..c028ed8 100644
--- a/test/options.cpp
+++ b/test/options.cpp
@@ -277,6 +277,122 @@ TEST_CASE("Providing options values via equal sign", "[options]")
   }
 }
 
+TEST_CASE("Valid/Invalid Option names", "[options]")
+{
+  const char prog_name[] = "test_invalid_opt_names";
+  std::vector<std::pair<std::string, std::string>> invalid_opts = {
+    {"Equals short name", "="},
+    {"Dash short name", "-"},
+    {"Long name starts with =", "a,=abcd"},
+    {"Long name starts with dash", "a,-abcd"},
+    {"Whitespace as name", " "},
+    {"Name is a space", "a, "},
+    {"Only comma delimiter given", ","},
+    {"Leading comma", ",a"},
+    {"Trailing comma after names", "a,ab,"},
+    {"Double comma", "a,,ab"},
+    {"Empty option name string", ""},
+    {"Control character in name", "\x03"},
+    {"Tab inside option name", "a,ab,\tac"},
+    {"Equals inside option name", "a,ab,ac,ab=cd"},
+    {"Two simple option names", "a,b"},
+  };
+
+  std::vector<std::pair<std::string, std::string>> valid_opts = {
+    {"Basic", "a,ab"},
+    {"Spaces", "a,     ab,       xyz"},
+    {"Arbitrary characters", "#,%%%,/><>?"},
+  };
+
+  for(const auto& t: invalid_opts) {
+    SECTION(t.first){
+      cxxopts::Options options(prog_name, " - Option names as invalid characters");
+        auto option_adder = options.add_options();
+        CHECK_THROWS(option_adder(t.second, "description", cxxopts::value<std::string>()));
+    }
+  }
+  for(const auto& t: valid_opts) {
+    SECTION(t.first){
+      cxxopts::Options options(prog_name, " - Option names as invalid characters");
+        auto option_adder = options.add_options();
+        CHECK_NOTHROW(option_adder(t.second, "description", cxxopts::value<std::string>()));
+    }
+  }
+}
+
+TEST_CASE("Option names as arbitrary characters and values parsing", "[options]")
+{
+  const char prog_name[] = "test_name_chars";
+  const char implicit_value[] = "implicit";
+  struct testcases
+  {
+    std::string name;
+    std::vector<std::string> opt_names;
+    Argv argv;
+    std::vector<std::pair<std::string, std::string>> expValues;
+    bool parseException;
+    bool setImplicit;
+  } tests[] = {
+    {
+      "Arbitrary chars",
+      {"#,^^","$$$"},
+      Argv{prog_name, "-#", "abc", "--$$$=@#$$"},
+      {{"#", "abc"}, {"$$$", "@#$$"}},
+      false,
+      false,
+    },
+    {
+      "Arbitrary chars and spaces",
+      {"*,   ab-cd","ab_cd"},
+      Argv{prog_name, "--ab-cd", "xyz","--ab_cd={}()"},
+      {{"ab-cd", "xyz"}, {"ab_cd", "{}()"}},
+      false,
+      false,
+    },
+    {
+      "Arbitrary character as single dot",
+      {"."},
+      Argv{prog_name, "-.=.."},
+      {{".", ".."}},
+      false,
+      false,
+    },
+    {
+      "Multiple Arbitrary characters as short options",
+      {"@",":","?","[","}","*","~","!"},
+      Argv{prog_name, "-@:?[}*~!"},
+      {{"@", implicit_value}, {"[", implicit_value}, {"!", implicit_value}},
+      false,
+      true,
+    }
+  };
+
+  for(const auto& tc : tests) {
+    SECTION(tc.name){
+        cxxopts::Options options(prog_name, " - Option names as arbitrary characters");
+        auto option_adder = options.add_options();
+        for(const auto& opt_name: tc.opt_names) {
+          if(tc.setImplicit){
+            option_adder(opt_name, "description", cxxopts::value<std::string>()->implicit_value(implicit_value));
+          }
+          else{
+            option_adder(opt_name, "description", cxxopts::value<std::string>());
+          }
+        }
+        if(tc.parseException) {
+          CHECK_THROWS(options.parse(tc.argv.argc(), tc.argv.argv()));
+          continue;
+        }
+        auto result = options.parse(tc.argv.argc(), tc.argv.argv());
+        for (const auto& p : tc.expValues) {
+          CHECK(result[p.first].as<std::string>() == p.second);
+        }
+
+    }
+  }
+}
+
+
 TEST_CASE("No positional", "[positional]")
 {
   cxxopts::Options options("test_no_positional",
@@ -951,7 +1067,7 @@ TEST_CASE("Allow bad short syntax", "[options]") {
 
   Argv av({
     "--ab?",
-    "-?b?#@"
+    "-=?b?#@"
   });
 
   auto** argv = av.argv();
@@ -965,7 +1081,7 @@ TEST_CASE("Allow bad short syntax", "[options]") {
     options.allow_unrecognised_options();
     CHECK_NOTHROW(options.parse(argc, argv));
     REQUIRE(argc == 2);
-    CHECK_THAT(argv[1], Catch::Equals("-?b?#@"));
+    CHECK_THAT(argv[1], Catch::Equals("-=?b?#@"));
   }
 }