diff --git a/pom.xml b/pom.xml
index 9e24029..5fb47c3 100644
--- a/pom.xml
+++ b/pom.xml
@@ -42,8 +42,8 @@
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <lucene-version>7.5.0</lucene-version>
-        <rascal-version>0.41.0-RC42</rascal-version>
-        <rascal-maven-version>0.30.0-RC25</rascal-maven-version>
+        <rascal-version>0.41.2</rascal-version>
+        <rascal-maven-version>0.30.3</rascal-maven-version>
         <maven.compiler.release>11</maven.compiler.release>
     </properties>
 
diff --git a/src/analysis/text/search/Grammars.rsc b/src/analysis/text/search/Grammars.rsc
index 2bc5de3..3a3f308 100644
--- a/src/analysis/text/search/Grammars.rsc
+++ b/src/analysis/text/search/Grammars.rsc
@@ -63,14 +63,14 @@ Tokenizer commentTokenizerFromGrammar(type[&T <: Tree] grammar) = tokenizer(list
      return [term(input, |lucene:///|(0, size(input)), "entire input")];
 });
 
-list[Tree] tokens(amb({Tree x, *_}), bool(Tree) isToken) = tokens(x, isToken);
+list[Tree] tokens(amb({Tree x, *_}), bool(Tree) isTokenPredicate) = tokens(x, isTokenPredicate);
 
-default list[Tree] tokens(Tree tok, bool(Tree) isToken) {
-  if (isToken(tok)) {
+default list[Tree] tokens(Tree tok, bool(Tree) isTokenPredicate) {
+  if (isTokenPredicate(tok)) {
     return [tok];
   }
   else {
-    return [*tokens(a, isToken) | tok has args, a <- tok.args];
+    return [*tokens(a, isTokenPredicate) | tok has args, a <- tok.args];
   }
 }