diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1f9266d7..01592c85 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -14,6 +14,7 @@ Bug fixes
 * Capturing an unknown variable in a closure no longer panics.
 * Fixes panic in interpolated strings with constant expressions.
 * Using `call_fn_raw` on a function without evaluating the AST no longer panics on namespace-qualified function calls due to `import` statements not run.
+* Some reserved tokens (such as "?", "++") cannot be used in custom syntax; this is now fixed.
 
 Breaking changes
 ----------------
diff --git a/src/tokenizer.rs b/src/tokenizer.rs
index c97b68b7..27333f42 100644
--- a/src/tokenizer.rs
+++ b/src/tokenizer.rs
@@ -873,6 +873,11 @@ impl Token {
             "**" => PowerOf,
             "**=" => PowerOfAssign,
 
+            #[cfg(feature = "no_object")]
+            "?." => Reserved(syntax.into()),
+            #[cfg(feature = "no_index")]
+            "?[" => Reserved(syntax.into()),
+
             #[cfg(not(feature = "no_function"))]
             "fn" => Fn,
             #[cfg(not(feature = "no_function"))]
@@ -892,9 +897,8 @@ impl Token {
             "import" | "export" | "as" => Reserved(syntax.into()),
 
             // List of reserved operators
-            "===" | "!==" | "->" | "<-" | ":=" | "~" | "::<" | "(*" | "*)" | "#" | "#!" => {
-                Reserved(syntax.into())
-            }
+            "===" | "!==" | "->" | "<-" | "?" | ":=" | ":;" | "~" | "!." | "::<" | "(*" | "*)"
+            | "#" | "#!" | "@" | "$" | "++" | "--" | "..." | "<|" | "|>" => Reserved(syntax.into()),
 
             // List of reserved keywords
             "public" | "protected" | "super" | "new" | "use" | "module" | "package" | "var"