diff --git a/jsx/lexer.py b/jsx/lexer.py
index 3668011..52fde53 100644
--- a/jsx/lexer.py
+++ b/jsx/lexer.py
@@ -5,50 +5,51 @@
 from pygments.token import Name, Operator, Punctuation, String, Text
 
 # Use same tokens as `JavascriptLexer`, but with tags and attributes support
-TOKENS = JavascriptLexer.tokens
-TOKENS.update(
-    {
-        "jsx": [
-            (
-                r"(<)(/?)(>)",
-                bygroups(Punctuation, Punctuation, Punctuation),
-            ),  # JSXFragment <>|</>
-            (r"(<)([\w]+)(\.?)", bygroups(Punctuation, Name.Tag, Punctuation), "tag"),
-            (
-                r"(<)(/)([\w]+)(>)",
-                bygroups(Punctuation, Punctuation, Name.Tag, Punctuation),
-            ),
-            (
-                r"(<)(/)([\w]+)",
-                bygroups(Punctuation, Punctuation, Name.Tag),
-                "fragment",
-            ),  # Same for React.Context
-        ],
-        "tag": [
-            (r"\s+", Text),
-            (r"([\w-]+\s*)(=)(\s*)", bygroups(Name.Attribute, Operator, Text), "attr"),
-            (r"[{}]+", Punctuation),
-            (r"[\w\.]+", Name.Attribute),
-            (r"(/?)(\s*)(>)", bygroups(Punctuation, Text, Punctuation), "#pop"),
-        ],
-        "fragment": [
-            (r"(.)([\w]+)", bygroups(Punctuation, Name.Attribute)),
-            (r"(>)", bygroups(Punctuation), "#pop"),
-        ],
-        "attr": [
-            ("{", Punctuation, "expression"),
-            ('".*?"', String, "#pop"),
-            ("'.*?'", String, "#pop"),
-            default("#pop"),
-        ],
-        "expression": [
-            ("{", Punctuation, "#push"),
-            ("}", Punctuation, "#pop"),
-            include("root"),
-        ],
-    }
-)
-TOKENS["root"].insert(0, include("jsx"))
+TOKENS = {
+    **JavascriptLexer.tokens,
+    "root": [
+        include("jsx"),
+        *JavascriptLexer.tokens["root"],
+    ],
+    "jsx": [
+        (
+            r"(<)(/?)(>)",
+            bygroups(Punctuation, Punctuation, Punctuation),
+        ),  # JSXFragment <>|</>
+        (r"(<)([\w]+)(\.?)", bygroups(Punctuation, Name.Tag, Punctuation), "tag"),
+        (
+            r"(<)(/)([\w]+)(>)",
+            bygroups(Punctuation, Punctuation, Name.Tag, Punctuation),
+        ),
+        (
+            r"(<)(/)([\w]+)",
+            bygroups(Punctuation, Punctuation, Name.Tag),
+            "fragment",
+        ),  # Same for React.Context
+    ],
+    "tag": [
+        (r"\s+", Text),
+        (r"([\w-]+\s*)(=)(\s*)", bygroups(Name.Attribute, Operator, Text), "attr"),
+        (r"[{}]+", Punctuation),
+        (r"[\w\.]+", Name.Attribute),
+        (r"(/?)(\s*)(>)", bygroups(Punctuation, Text, Punctuation), "#pop"),
+    ],
+    "fragment": [
+        (r"(.)([\w]+)", bygroups(Punctuation, Name.Attribute)),
+        (r"(>)", bygroups(Punctuation), "#pop"),
+    ],
+    "attr": [
+        ("{", Punctuation, "expression"),
+        ('".*?"', String, "#pop"),
+        ("'.*?'", String, "#pop"),
+        default("#pop"),
+    ],
+    "expression": [
+        ("{", Punctuation, "#push"),
+        ("}", Punctuation, "#pop"),
+        include("root"),
+    ],
+}
 
 
 class JsxLexer(JavascriptLexer):