diff --git a/include/external/clara.h b/include/external/clara.h
index 51aca828..6ab30136 100644
--- a/include/external/clara.h
+++ b/include/external/clara.h
@@ -6,7 +6,7 @@
  *  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
  */
 
-// Version 0.0.2.3
+// Version 0.0.2.4
 
 // Only use header guard if we are not using an outer namespace
 #if !defined(TWOBLUECUBES_CLARA_H_INCLUDED) || defined(STITCH_CLARA_OPEN_NAMESPACE)
@@ -589,7 +589,7 @@ namespace Clara {
             }
         }
         Mode handleOpt( std::size_t i, char c, std::string const& arg, std::vector<Token>& tokens ) {
-            if( std::string( " \t:=\0", 5 ).find( c ) == std::string::npos )
+            if( std::string( ":=\0", 5 ).find( c ) == std::string::npos )
                 return mode;
 
             std::string optName = arg.substr( from, i-from );
@@ -603,7 +603,7 @@ namespace Clara {
             return None;
         }
         Mode handlePositional( std::size_t i, char c, std::string const& arg, std::vector<Token>& tokens ) {
-            if( inQuotes || std::string( " \t\0", 3 ).find( c ) == std::string::npos )
+            if( inQuotes || std::string( "\0", 3 ).find( c ) == std::string::npos )
                 return mode;
 
             std::string data = arg.substr( from, i-from );