diff --git a/src/Regex/P6Regex/Grammar.pm b/src/Regex/P6Regex/Grammar.pm
index 3b2e965..9fab92d 100644
--- a/src/Regex/P6Regex/Grammar.pm
+++ b/src/Regex/P6Regex/Grammar.pm
@@ -9,6 +9,8 @@ grammar Regex::P6Regex::Grammar is HLL::Grammar;
 
     token normspace { <?before \s | '#' > <.ws> }
 
+    token identifier { <.ident> [ <[\-']> <.ident> ]* }
+
     token arg {
         [
         | <?[']> <quote_EXPR: ':q'>
@@ -145,7 +147,7 @@ grammar Regex::P6Regex::Grammar is HLL::Grammar;
     }
 
     token assertion:sym<name> {
-        $<longname>=[\w+]
+        <longname=.identifier>
             [
             | <?before '>'>
             | '=' <assertion>
diff --git a/t/p6regex/01-regex.t b/t/p6regex/01-regex.t
index 07b5499..7bb58ae 100644
--- a/t/p6regex/01-regex.t
+++ b/t/p6regex/01-regex.t
@@ -52,6 +52,8 @@ Description of the test.
 
 =cut
 
+.loadlib 'io_ops'
+
 .const string TESTS = 'no_plan'
 
 .sub main :main