diff --git a/demos/LevelOrderTraversal.tri b/demos/LevelOrderTraversal.tri
index 7681b28..06b21ae 100644
--- a/demos/LevelOrderTraversal.tri
+++ b/demos/LevelOrderTraversal.tri
@@ -61,7 +61,7 @@ exampleOne = flatLOT [("1")
                        [("2") [("4") t t] t]
                        [("3") [("5") t t] [("6") t t]]]
 
-exampleTwo = flatLOT [[("1")
+exampleTwo = flatLOT [("1")
                        [("2") [("4") [("8") t t] [("9") t t]] [("6") [("10") t t] [("12") t t]]]
                        [("3") [("5") [("11") t t] t] [("7") t t]]]
 
diff --git a/src/Parser.hs b/src/Parser.hs
index c9faf52..02dea23 100644
--- a/src/Parser.hs
+++ b/src/Parser.hs
@@ -25,14 +25,10 @@ satisfyM f = do
   return token
 
 updateDepth :: LToken -> PState -> PState
-updateDepth LOpenParen st = st { parenDepth = parenDepth st + 1 }
-updateDepth LCloseParen st
-  | parenDepth st > 0 = st { parenDepth = parenDepth st - 1 }
-  | otherwise         = errorWithoutStackTrace "Unmatched closing parentheses"
-updateDepth LOpenBracket st = st { bracketDepth = bracketDepth st + 1 }
-updateDepth LCloseBracket st
-  | bracketDepth st > 0 = st { bracketDepth = bracketDepth st - 1 }
-  | otherwise           = errorWithoutStackTrace "Unmatched closing bracket"
+updateDepth LOpenParen    st = st { parenDepth   = parenDepth st   + 1 }
+updateDepth LOpenBracket  st = st { bracketDepth = bracketDepth st + 1 }
+updateDepth LCloseParen   st = st { parenDepth   = parenDepth st   - 1 }
+updateDepth LCloseBracket st = st { bracketDepth = bracketDepth st - 1 }
 updateDepth _ st = st
 
 topLevelNewline :: ParserM ()