diff --git a/.changeset/cold-chefs-cheat.md b/.changeset/cold-chefs-cheat.md
new file mode 100644
index 000000000000..a65b5304b48a
--- /dev/null
+++ b/.changeset/cold-chefs-cheat.md
@@ -0,0 +1,5 @@
+---
+swc_ecma_ast: patch
+---
+
+fix(es/base): Accept any case of EsVersion during deserialization
diff --git a/crates/swc/tests/fixture/issues-9xxx/9287/input/.swcrc b/crates/swc/tests/fixture/issues-9xxx/9287/input/.swcrc
new file mode 100644
index 000000000000..82505b21febd
--- /dev/null
+++ b/crates/swc/tests/fixture/issues-9xxx/9287/input/.swcrc
@@ -0,0 +1,8 @@
+{
+  "jsc": {
+    "parser": {
+      "syntax": "ecmascript"
+    },
+    "target": "ESNEXT"
+  }
+}
\ No newline at end of file
diff --git a/crates/swc/tests/fixture/issues-9xxx/9287/input/index.js b/crates/swc/tests/fixture/issues-9xxx/9287/input/index.js
new file mode 100644
index 000000000000..8f8128a22e93
--- /dev/null
+++ b/crates/swc/tests/fixture/issues-9xxx/9287/input/index.js
@@ -0,0 +1 @@
+function foo() { }
\ No newline at end of file
diff --git a/crates/swc/tests/fixture/issues-9xxx/9287/output/index.js b/crates/swc/tests/fixture/issues-9xxx/9287/output/index.js
new file mode 100644
index 000000000000..b0400ee9b26e
--- /dev/null
+++ b/crates/swc/tests/fixture/issues-9xxx/9287/output/index.js
@@ -0,0 +1 @@
+function foo() {}
diff --git a/crates/swc_ecma_ast/src/lib.rs b/crates/swc_ecma_ast/src/lib.rs
index 966df8481d6e..368e441e6caf 100644
--- a/crates/swc_ecma_ast/src/lib.rs
+++ b/crates/swc_ecma_ast/src/lib.rs
@@ -107,36 +107,49 @@ impl Take for Invalid {
 /// Note: This type implements `Serailize` and `Deserialize` if `serde` is
 /// enabled, instead of requiring `serde-impl` feature.
 #[derive(Debug, Default, Clone, Copy, PartialOrd, Ord, PartialEq, Eq, Hash)]
-#[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
+#[cfg_attr(feature = "serde", derive(Serialize))]
+#[cfg_attr(feature = "serde", serde(rename_all = "lowercase"))]
 pub enum EsVersion {
-    #[cfg_attr(feature = "serde", serde(rename = "es3", alias = "ES3"))]
     Es3,
-    #[cfg_attr(feature = "serde", serde(rename = "es5", alias = "ES5"))]
     #[default]
     Es5,
-    #[cfg_attr(
-        feature = "serde",
-        serde(rename = "es2015", alias = "ES2015", alias = "ES6", alias = "es6")
-    )]
     Es2015,
-    #[cfg_attr(feature = "serde", serde(rename = "es2016", alias = "ES2016"))]
     Es2016,
-    #[cfg_attr(feature = "serde", serde(rename = "es2017", alias = "ES2017"))]
     Es2017,
-    #[cfg_attr(feature = "serde", serde(rename = "es2018", alias = "ES2018"))]
     Es2018,
-    #[cfg_attr(feature = "serde", serde(rename = "es2019", alias = "ES2019"))]
     Es2019,
-    #[cfg_attr(feature = "serde", serde(rename = "es2020", alias = "ES2020"))]
     Es2020,
-    #[cfg_attr(feature = "serde", serde(rename = "es2021", alias = "ES2021"))]
     Es2021,
-    #[cfg_attr(feature = "serde", serde(rename = "es2022", alias = "ES2022"))]
     Es2022,
-    #[cfg_attr(feature = "serde", serde(rename = "esnext", alias = "EsNext"))]
     EsNext,
 }
 
+#[cfg(feature = "serde")]
+impl<'de> Deserialize<'de> for EsVersion {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: serde::Deserializer<'de>,
+    {
+        use serde::de::Error;
+
+        let s = String::deserialize(deserializer)?;
+        match s.to_lowercase().as_str() {
+            "es3" => Ok(EsVersion::Es3),
+            "es5" => Ok(EsVersion::Es5),
+            "es2015" | "es6" => Ok(EsVersion::Es2015),
+            "es2016" => Ok(EsVersion::Es2016),
+            "es2017" => Ok(EsVersion::Es2017),
+            "es2018" => Ok(EsVersion::Es2018),
+            "es2019" => Ok(EsVersion::Es2019),
+            "es2020" => Ok(EsVersion::Es2020),
+            "es2021" => Ok(EsVersion::Es2021),
+            "es2022" => Ok(EsVersion::Es2022),
+            "esnext" => Ok(EsVersion::EsNext),
+            _ => Err(D::Error::custom(format!("Unknown ES version: {}", s))),
+        }
+    }
+}
+
 impl EsVersion {
     pub const fn latest() -> Self {
         EsVersion::EsNext