diff --git a/bashlex/parser.py b/bashlex/parser.py
index ddf59066..45814095 100644
--- a/bashlex/parser.py
+++ b/bashlex/parser.py
@@ -598,7 +598,10 @@ def parse(s, strictmode=True, expansionlimit=None, convertpos=False):
     command substitutions found during word expansion.
     '''
     p = _parser(s, strictmode=strictmode, expansionlimit=expansionlimit)
-    parts = [p.parse()]
+    tree = p.parse()
+    if not tree:
+        return []
+    parts = [tree]
 
     class endfinder(ast.nodevisitor):
         def __init__(self):
diff --git a/tests/test-parser.py b/tests/test-parser.py
index 3a6ce180..ab210028 100644
--- a/tests/test-parser.py
+++ b/tests/test-parser.py
@@ -111,6 +111,11 @@ def assertASTsEquals(self, s, expectedlist, **parserargs):
             msg = 'ASTs not equal for %r\n\nresult:\n\n%s\n\n!=\n\nexpected:\n\n%s' % (s, result.dump(), expected.dump())
             self.assertEquals(result, expected, msg)
 
+    def test_comment(self):
+        s = '# comment'
+        results = parse(s)
+        self.assertEquals(results, [], 'expected empty tree for comment')
+
     def test_command(self):
         s = 'a b c'
         self.assertASTEquals(s,