diff --git a/crates/oxc_isolated_declarations/src/class.rs b/crates/oxc_isolated_declarations/src/class.rs
index 0316624b8..cadaa08d5 100644
--- a/crates/oxc_isolated_declarations/src/class.rs
+++ b/crates/oxc_isolated_declarations/src/class.rs
@@ -238,7 +238,7 @@ impl<'a> IsolatedDeclarations<'a> {
     ) -> oxc_allocator::Vec<'a, ClassElement<'a>> {
         let mut elements = self.ast.new_vec();
         for (index, param) in function.params.items.iter().enumerate() {
-            if param.accessibility.is_some() {
+            if param.accessibility.is_some() || param.readonly {
                 // transformed params will definitely have type annotation
                 let type_annotation = self.ast.copy(&params.items[index].pattern.type_annotation);
                 if let Some(new_element) =
diff --git a/crates/oxc_isolated_declarations/src/function.rs b/crates/oxc_isolated_declarations/src/function.rs
index 12c7278f6..bb581f3e3 100644
--- a/crates/oxc_isolated_declarations/src/function.rs
+++ b/crates/oxc_isolated_declarations/src/function.rs
@@ -106,14 +106,7 @@ impl<'a> IsolatedDeclarations<'a> {
             );
         }
 
-        Some(self.ast.formal_parameter(
-            param.span,
-            pattern,
-            None,
-            param.readonly,
-            false,
-            self.ast.new_vec(),
-        ))
+        Some(self.ast.formal_parameter(param.span, pattern, None, false, false, self.ast.new_vec()))
     }
 
     pub fn transform_formal_parameters(
diff --git a/crates/oxc_isolated_declarations/tests/fixtures/class.ts b/crates/oxc_isolated_declarations/tests/fixtures/class.ts
index e5a4f40dd..ae8b2713f 100644
--- a/crates/oxc_isolated_declarations/tests/fixtures/class.ts
+++ b/crates/oxc_isolated_declarations/tests/fixtures/class.ts
@@ -22,3 +22,11 @@ export class Baz {
   readonly prop1 = 'some string';
   prop2 = 'another string';
 }
+
+export class Boo {
+  constructor(
+    public readonly prop: number = 0,
+    private readonly prop2: number = 1,
+    readonly prop3: number = 1,
+  ) {}
+}
diff --git a/crates/oxc_isolated_declarations/tests/snapshots/class.snap b/crates/oxc_isolated_declarations/tests/snapshots/class.snap
index 2a754eedc..5a598fed7 100644
--- a/crates/oxc_isolated_declarations/tests/snapshots/class.snap
+++ b/crates/oxc_isolated_declarations/tests/snapshots/class.snap
@@ -22,3 +22,9 @@ export declare class Baz {
 	readonly prop1: 'some string';
 	prop2: string;
 }
+export declare class Boo {
+	readonly prop: number;
+	private readonly prop2: number;
+	readonly prop3: number;
+	constructor(prop?: number, prop2?: number, prop3?: number);
+}