diff --git a/apps/oxlint/conformance/snapshot.md b/apps/oxlint/conformance/snapshot.md
index 08b5873d3bc58..45349e0dc41c7 100644
--- a/apps/oxlint/conformance/snapshot.md
+++ b/apps/oxlint/conformance/snapshot.md
@@ -7,8 +7,8 @@
 | Status            | Count | %      |
 | ----------------- | ----- | ------ |
 | Total rules       |   277 | 100.0% |
-| Fully passing     |   219 |  79.1% |
-| Partially passing |    58 |  20.9% |
+| Fully passing     |   220 |  79.4% |
+| Partially passing |    57 |  20.6% |
 | Fully failing     |     0 |   0.0% |
 | Load errors       |     0 |   0.0% |
 | No tests run      |     0 |   0.0% |
@@ -18,8 +18,8 @@
 | Status      | Count | %      |
 | ----------- | ----- | ------ |
 | Total tests | 29765 | 100.0% |
-| Passing     | 28684 |  96.4% |
-| Failing     |   974 |   3.3% |
+| Passing     | 28686 |  96.4% |
+| Failing     |   972 |   3.3% |
 | Skipped     |   107 |   0.4% |
 
 ## Fully Passing Rules
@@ -172,6 +172,7 @@
 - `no-sequences` (42 tests)
 - `no-spaced-func` (28 tests)
 - `no-sparse-arrays` (6 tests)
+- `no-sync` (10 tests)
 - `no-tabs` (11 tests)
 - `no-template-curly-in-string` (22 tests)
 - `no-ternary` (4 tests)
@@ -282,7 +283,6 @@
 - `no-setter-return` - 161 / 164 (98.2%)
 - `no-shadow-restricted-names` - 43 / 44 (97.7%)
 - `no-shadow` - 300 / 308 (97.4%)
-- `no-sync` - 8 / 10 (80.0%)
 - `no-trailing-spaces` - 53 / 54 (98.1%)
 - `no-undef` - 54 / 94 (57.4%)
 - `no-undefined` - 37 / 53 (69.8%)
@@ -81358,80 +81358,6 @@ AssertionError [ERR_ASSERTION]: Should have 1 error but had 0: []
     at apps/oxlint/dist/index.js
 
 
-### `no-sync`
-
-Pass: 8 / 10 (80.0%)
-Fail: 2 / 10 (20.0%)
-Skip: 0 / 10 (0.0%)
-
-#### no-sync > invalid
-
-```js
-function someFunction() {fs.fooSync();}
-```
-
-```json
-{
-  "options": [
-    {
-      "allowAtRootLevel": true
-    }
-  ],
-  "errors": [
-    {
-      "messageId": "noSync",
-      "data": {
-        "propertyName": "fooSync"
-      }
-    }
-  ]
-}
-```
-
-AssertionError [ERR_ASSERTION]: Should have 1 error but had 0: []
-
-0 !== 1
-
-    at assertErrorCountIsCorrect (apps/oxlint/dist/index.js)
-    at assertInvalidTestCasePasses (apps/oxlint/dist/index.js)
-    at runInvalidTestCase (apps/oxlint/dist/index.js)
-    at apps/oxlint/dist/index.js
-
-
-#### no-sync > invalid
-
-```js
-var a = function someFunction() {fs.fooSync();}
-```
-
-```json
-{
-  "options": [
-    {
-      "allowAtRootLevel": true
-    }
-  ],
-  "errors": [
-    {
-      "messageId": "noSync",
-      "data": {
-        "propertyName": "fooSync"
-      }
-    }
-  ]
-}
-```
-
-AssertionError [ERR_ASSERTION]: Should have 1 error but had 0: []
-
-0 !== 1
-
-    at assertErrorCountIsCorrect (apps/oxlint/dist/index.js)
-    at assertInvalidTestCasePasses (apps/oxlint/dist/index.js)
-    at runInvalidTestCase (apps/oxlint/dist/index.js)
-    at apps/oxlint/dist/index.js
-
-
 ### `no-trailing-spaces`
 
 Pass: 53 / 54 (98.1%)
diff --git a/apps/oxlint/src-js/plugins/selector.ts b/apps/oxlint/src-js/plugins/selector.ts
index 9c74efc589b23..4e1de27361f44 100644
--- a/apps/oxlint/src-js/plugins/selector.ts
+++ b/apps/oxlint/src-js/plugins/selector.ts
@@ -17,10 +17,35 @@ type NodeTypeId = number;
 const ESQUERY_OPTIONS: ESQueryOptions = {
   nodeTypeKey: "type",
   visitorKeys,
-  fallback: (node: EsqueryNode) => Object.keys(node).filter(filterKey),
-  matchClass: (_className: unknown, _node: EsqueryNode, _ancestors: EsqueryNode[]) => false, // TODO: Is this right?
+  fallback(node: EsqueryNode) {
+    // Our visitor keys should cover all AST node types
+    throw new Error(`Unknown node type: ${node.type}`);
+  },
+  matchClass: matchesSelectorClass,
 };
-const filterKey = (key: string) => key !== "parent" && key !== "range" && key !== "loc";
+
+/**
+ * Check if an AST node matches a selector class.
+ * @param className - Class name parsed from selector
+ * @param node - AST node
+ * @param _ancestors - AST node's ancestors
+ * @returns `true` if node matches class
+ */
+function matchesSelectorClass(
+  className: string,
+  node: EsqueryNode,
+  _ancestors: EsqueryNode[],
+): boolean {
+  if (className.toLowerCase() === "function") {
+    const { type } = node;
+    return (
+      type === "FunctionDeclaration" ||
+      type === "FunctionExpression" ||
+      type === "ArrowFunctionExpression"
+    );
+  }
+  return false;
+}
 
 // Specificity is a combination of:
 //
@@ -230,7 +255,7 @@ function analyzeSelector(
       // TODO: Should TS function types be included in `FUNCTION_NODE_TYPE_IDS`?
       // This TODO comment is from ESLint's implementation. Not sure what it means!
       // TODO: Abstract into JSLanguage somehow.
-      if (esquerySelector.name === "function") return FUNCTION_NODE_TYPE_IDS;
+      if (esquerySelector.name.toLowerCase() === "function") return FUNCTION_NODE_TYPE_IDS;
       selector.isComplex = true;
       return null;
 
diff --git a/apps/oxlint/test/compile_visitor.test.ts b/apps/oxlint/test/compile_visitor.test.ts
index bd3beb57b71fd..f3f7932f7915c 100644
--- a/apps/oxlint/test/compile_visitor.test.ts
+++ b/apps/oxlint/test/compile_visitor.test.ts
@@ -578,7 +578,8 @@ describe("compile visitor", () => {
       const exit2 = vi.fn(() => {});
       addVisitorToCompiled({
         ":function": enter2,
-        ":function:exit": exit2,
+        // Check case insensitivity
+        ":FunCtioN:exit": exit2,
       });
 
       expect(finalizeCompiledVisitor()).toBe(true);
diff --git a/apps/oxlint/test/fixtures/selector/output.snap.md b/apps/oxlint/test/fixtures/selector/output.snap.md
index 07310e4ff0993..0af53996de188 100644
--- a/apps/oxlint/test/fixtures/selector/output.snap.md
+++ b/apps/oxlint/test/fixtures/selector/output.snap.md
@@ -68,7 +68,7 @@
   | *:exit: VariableDeclarator
   | *:exit: VariableDeclaration
   | *: FunctionDeclaration(foo)
-  | :function: FunctionDeclaration(foo)
+  | :FUNCTION: FunctionDeclaration(foo)
   | :not(Identifier): FunctionDeclaration(foo)
   | :matches(Identifier, FunctionDeclaration): FunctionDeclaration(foo)
   | Program > FunctionDeclaration: FunctionDeclaration(foo)
@@ -77,6 +77,7 @@
   | :matches(ObjectExpression > SpreadElement, FunctionDeclaration): FunctionDeclaration(foo)
   | :matches(Identifier[name=a], FunctionDeclaration[id.name=foo]): FunctionDeclaration(foo)
   | *: Identifier(foo)
+  | :function > Identifier: Identifier(foo)
   | Identifier: Identifier(foo)
   | :matches(Identifier, FunctionDeclaration): Identifier(foo)
   | *:exit: Identifier(foo)
@@ -85,7 +86,7 @@
   | *:exit: BlockStatement
   | *:exit: FunctionDeclaration(foo)
   | *: FunctionDeclaration(bar)
-  | :function: FunctionDeclaration(bar)
+  | :FUNCTION: FunctionDeclaration(bar)
   | :not(Identifier): FunctionDeclaration(bar)
   | :matches(Identifier, FunctionDeclaration): FunctionDeclaration(bar)
   | Program > FunctionDeclaration: FunctionDeclaration(bar)
@@ -93,6 +94,7 @@
   | :matches(ObjectExpression > SpreadElement, FunctionDeclaration): FunctionDeclaration(bar)
   | :matches(ObjectExpression > SpreadElement, FunctionDeclaration[id.name=bar]): FunctionDeclaration(bar)
   | *: Identifier(bar)
+  | :function > Identifier: Identifier(bar)
   | Identifier: Identifier(bar)
   | :matches(Identifier, FunctionDeclaration): Identifier(bar)
   | *:exit: Identifier(bar)
@@ -103,7 +105,7 @@
   | *: ExpressionStatement
   | :not(Identifier): ExpressionStatement
   | *: ArrowFunctionExpression
-  | :function: ArrowFunctionExpression
+  | :FUNCTION: ArrowFunctionExpression
   | :not(Identifier): ArrowFunctionExpression
   | *: BlockStatement
   | :not(Identifier): BlockStatement
diff --git a/apps/oxlint/test/fixtures/selector/plugin.ts b/apps/oxlint/test/fixtures/selector/plugin.ts
index aef9474c81b9b..6745afe73f594 100644
--- a/apps/oxlint/test/fixtures/selector/plugin.ts
+++ b/apps/oxlint/test/fixtures/selector/plugin.ts
@@ -21,7 +21,8 @@ const plugin: Plugin = {
           // :not
           ":not(Identifier)",
           // class
-          ":function",
+          ":FUNCTION",
+          ":function > Identifier",
           // Child
           "Property > Identifier",
           "ObjectExpression > Identifier", // does not match