diff --git a/src/syn/lexer.rs b/src/syn/lexer.rs
index 1093f0b..6d6cc56 100644
--- a/src/syn/lexer.rs
+++ b/src/syn/lexer.rs
@@ -8,9 +8,9 @@ lazy_static! {
         r#"^(
             (?P<float>[-+]?[0-9]+\.[0-9]+([eE][+\-][0-9]+)?)
         |   (?P<int>[-+]?[0-9]+)
-        |   (?P<assign>:[a-zA-Z_?\-*+/=.'@$%^&|][0-9a-zA-Z_?\-*+/=.'@$%^&|]*)
+        |   (?P<assign>:[a-zA-Z_?\-*+/=.'@$%^&|~][0-9a-zA-Z_?\-*+/=.'@$%^&|~]*)
         |   (?P<meta>%[a-zA-Z0-9\-_]+)
-        |   (?P<word>[a-zA-Z_?\-*+/=.'@$%^&|][0-9a-zA-Z_?\-*+/=.'@$%^&|]*)
+        |   (?P<word>[a-zA-Z_?\-*+/=.'@$%^&|~][0-9a-zA-Z_?\-*+/=.'@$%^&|~]*)
         |   (?P<lquote>\[)
         |   (?P<rquote>\])
         |   (?P<apply>!)
@@ -168,7 +168,7 @@ mod test {
 
     #[test]
     fn test_word() {
-        let mut lexer = Lexer::new("test", r"a b c d foo bar baz = == === =a ==a ===a");
+        let mut lexer = Lexer::new("test", r"a b c d foo bar baz = == === =a ==a ===a ~= ~==");
         assert_token!(lexer, Token::Word, "a");
         assert_token!(lexer, Token::Word, "b");
         assert_token!(lexer, Token::Word, "c");
@@ -184,18 +184,21 @@ mod test {
         assert_token!(lexer, Token::Word, "=a");
         assert_token!(lexer, Token::Word, "==a");
         assert_token!(lexer, Token::Word, "===a");
+        assert_token!(lexer, Token::Word, "~=");
+        assert_token!(lexer, Token::Word, "~==");
 
         assert!(lexer.is_eof());
     }
 
     #[test]
     fn test_assign() {
-        let mut lexer = Lexer::new("test", r":a := :foo :foo-bar :foo-bar-baz");
+        let mut lexer = Lexer::new("test", r":a := :foo :foo-bar :foo-bar-baz :foo~bar~baz");
         assert_token!(lexer, Token::Assign, ":a");
         assert_token!(lexer, Token::Assign, ":=");
         assert_token!(lexer, Token::Assign, ":foo");
         assert_token!(lexer, Token::Assign, ":foo-bar");
         assert_token!(lexer, Token::Assign, ":foo-bar-baz");
+        assert_token!(lexer, Token::Assign, ":foo~bar~baz");
         assert!(lexer.is_eof());
     }