diff --git a/corpus/commands.txt b/corpus/commands.txt
index ef20fcc..f44f498 100644
--- a/corpus/commands.txt
+++ b/corpus/commands.txt
@@ -110,3 +110,24 @@ Negated command
     (command_name
       (identifier))
     (word)))
+
+===============================
+Mix functions and commands
+===============================
+
+generate() | cut -d ' ' -f 1
+
+---
+
+(source_file
+  (pipeline
+    (call_expression
+      (identifier)
+      (argument_list))
+    (command
+      (command_name
+        (identifier))
+          (word)
+          (raw_string)
+          (word)
+          (word))))
diff --git a/grammar.js b/grammar.js
index a0ae8e2..3df1040 100644
--- a/grammar.js
+++ b/grammar.js
@@ -25,7 +25,6 @@ module.exports = grammar({
       $.variable_declaration,
       $._statement,
       $.return,
-      $.while,
       'break',
       'continue',
     ),
@@ -74,6 +73,7 @@ module.exports = grammar({
     _statement: $ => choice(
       $.command,
       $.pipeline,
+      $.while,
       seq('!', $.command),
       $._expression,
     ),
@@ -174,7 +174,7 @@ module.exports = grammar({
     line_comment: $ => token(seq('//', /.*/)),
     block_comment: $ => token(seq('/*', /[^*]*\*+([^/*][^*]*\*+)*/, '/')),
     identifier: $ => /[a-zA-Z_][a-zA-Z0-9_]*/,
-    word: $ => /[^#'"\\\s$<>{}&;]+/,
+    word: $ => /[^#'"\\\s$<>{}&;()]+/,
     number: $ => /\d+/,
     boolean: $ => choice('true', 'false'),
     template_string: $ => seq(