diff --git a/ablescript/src/error.rs b/ablescript/src/error.rs
index 195a271..46f9d86 100644
--- a/ablescript/src/error.rs
+++ b/ablescript/src/error.rs
@@ -12,6 +12,9 @@ pub enum ErrorKind {
     /// Parser expected token, but none was available
     UnexpectedEoi,
 
+    /// Parser encountered unknown token
+    InvalidToken,
+
     /// Parser expected certain token, but other one appeared
     UnexpectedToken(Token),
 
@@ -65,6 +68,7 @@ impl Display for ErrorKind {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match self {
             ErrorKind::UnexpectedEoi => write!(f, "unexpected end of input"),
+            ErrorKind::InvalidToken => write!(f, "invalid token"),
             ErrorKind::UnexpectedToken(Token::Melo) => write!(f, "unexpected marten"),
             ErrorKind::UnexpectedToken(token) => write!(f, "unexpected token {:?}", token),
             ErrorKind::UnknownVariable(name) => write!(f, "unknown identifier \"{}\"", name),
diff --git a/ablescript/src/parser.rs b/ablescript/src/parser.rs
index 5cd89ab..5b1cc53 100644
--- a/ablescript/src/parser.rs
+++ b/ablescript/src/parser.rs
@@ -34,6 +34,9 @@ impl<'source> Parser<'source> {
                 // Ignore comments
                 Token::Comment => continue,
 
+                // Invalid token
+                Token::Error => return Err(Error::new(ErrorKind::InvalidToken, self.lexer.span())),
+
                 // T-Dark block (replace `lang` with `script`)
                 Token::TDark => ast.extend(self.tdark_flow()?),
                 token => ast.push(self.parse_stmt(token)?),
@@ -53,6 +56,7 @@ impl<'source> Parser<'source> {
                 .ok_or_else(|| Error::unexpected_eoi(self.lexer.span().start))?
             {
                 Token::Comment => (),
+                Token::Error => break Err(Error::new(ErrorKind::InvalidToken, self.lexer.span())),
                 token => break Ok(token),
             }
         }
@@ -256,10 +260,7 @@ impl<'source> Parser<'source> {
                     .ok_or_else(|| Error::new(ErrorKind::MissingLhs, self.lexer.span()))?,
             ),
             rhs: {
-                let next = self
-                    .lexer
-                    .next()
-                    .ok_or_else(|| Error::unexpected_eoi(self.lexer.span().start))?;
+                let next = self.checked_next()?;
                 Box::new(self.parse_expr(next, &mut None)?)
             },
             kind,