diff --git a/src/Language/PHP/Assignment.hs b/src/Language/PHP/Assignment.hs
index 4d2ce02ba..09e2655c4 100644
--- a/src/Language/PHP/Assignment.hs
+++ b/src/Language/PHP/Assignment.hs
@@ -35,6 +35,7 @@ type Syntax = '[
   , Declaration.VariableDeclaration
   , Syntax.Identifier
   , Syntax.VariableName
+  , Syntax.RequireOnce
   , [] ]
 
 type Term = Term.Term (Data.Union.Union Syntax) (Record Location)
@@ -84,10 +85,12 @@ expression = choice [
   -- includeExpression,
   -- includeOnceExpression,
   -- requireExpression,
-  -- requireOnceExpression
+  requireOnceExpression
   ]
 
--- TODO: Does this keep the range of VariableName?
+requireOnceExpression :: Assignment
+requireOnceExpression = makeTerm <$> symbol RequireOnceExpression <*> children (Syntax.RequireOnce <$> expression)
+
 variableName :: Assignment
 variableName = makeTerm <$> symbol VariableName <*> children (Syntax.VariableName <$> name)
 
diff --git a/src/Language/PHP/Syntax.hs b/src/Language/PHP/Syntax.hs
index 66973702a..29f101ecd 100644
--- a/src/Language/PHP/Syntax.hs
+++ b/src/Language/PHP/Syntax.hs
@@ -8,7 +8,6 @@ import Data.Functor.Classes.Generic
 import Data.Mergeable
 import GHC.Generics
 
--- | Lookup type for a type-level key in a typescript map.
 newtype Text a = Text ByteString
   deriving (Diffable, Eq, Foldable, Functor, GAlign, Generic1, Mergeable, Ord, Show, Traversable)
 
@@ -16,10 +15,16 @@ instance Eq1 Text where liftEq = genericLiftEq
 instance Ord1 Text where liftCompare = genericLiftCompare
 instance Show1 Text where liftShowsPrec = genericLiftShowsPrec
 
--- | Lookup type for a type-level key in a typescript map.
-data VariableName a = VariableName a
+newtype VariableName a = VariableName a
   deriving (Diffable, Eq, Foldable, Functor, GAlign, Generic1, Mergeable, Ord, Show, Traversable)
 
 instance Eq1 VariableName where liftEq = genericLiftEq
 instance Ord1 VariableName where liftCompare = genericLiftCompare
 instance Show1 VariableName where liftShowsPrec = genericLiftShowsPrec
+
+newtype RequireOnce a = RequireOnce a
+  deriving (Diffable, Eq, Foldable, Functor, GAlign, Generic1, Mergeable, Ord, Show, Traversable)
+
+instance Eq1 RequireOnce where liftEq = genericLiftEq
+instance Ord1 RequireOnce where liftCompare = genericLiftCompare
+instance Show1 RequireOnce where liftShowsPrec = genericLiftShowsPrec