diff --git a/crates/oxc_transformer/src/typescript/namespace.rs b/crates/oxc_transformer/src/typescript/namespace.rs
index 87d2f3ead..4f5a70f9f 100644
--- a/crates/oxc_transformer/src/typescript/namespace.rs
+++ b/crates/oxc_transformer/src/typescript/namespace.rs
@@ -280,15 +280,34 @@ impl<'a> TypeScript<'a> {
         &self,
         arg_name: Atom<'a>,
         real_name: Atom<'a>,
-        stmts: Vec<'a, Statement<'a>>,
+        mut stmts: Vec<'a, Statement<'a>>,
         parent_export: Option<Expression<'a>>,
         scope_id: ScopeId,
         ctx: &mut TraverseCtx,
     ) -> Statement<'a> {
+        let mut directives = self.ctx.ast.new_vec();
+
+        // Check if the namespace has a `use strict` directive
+        if stmts.first().is_some_and(|stmt| {
+            matches!(stmt, Statement::ExpressionStatement(es) if
+                matches!(&es.expression, Expression::StringLiteral(literal) if
+                literal.value == "use strict")
+            )
+        }) {
+            stmts.remove(0);
+            let directive = self.ctx.ast.new_atom("use strict");
+            let directive = Directive {
+                span: SPAN,
+                expression: StringLiteral::new(SPAN, directive.clone()),
+                directive,
+            };
+            directives.push(directive);
+        }
+
         // `(function (_N) { var x; })(N || (N = {}))`;
         //  ^^^^^^^^^^^^^^^^^^^^^^^^^^
         let callee = {
-            let body = self.ctx.ast.function_body(SPAN, self.ctx.ast.new_vec(), stmts);
+            let body = self.ctx.ast.function_body(SPAN, directives, stmts);
             let params = {
                 let ident =
                     self.ctx.ast.binding_pattern_identifier(BindingIdentifier::new(SPAN, arg_name));
diff --git a/tasks/coverage/transformer_typescript.snap b/tasks/coverage/transformer_typescript.snap
index b31f57b09..33778c92c 100644
--- a/tasks/coverage/transformer_typescript.snap
+++ b/tasks/coverage/transformer_typescript.snap
@@ -2,10 +2,9 @@ commit: 64d2eeea
 
 transformer_typescript Summary:
 AST Parsed     : 5243/5243 (100.00%)
-Positive Passed: 5237/5243 (99.89%)
+Positive Passed: 5238/5243 (99.90%)
 Mismatch: "compiler/elidedEmbeddedStatementsReplacedWithSemicolon.ts"
 Mismatch: "compiler/jsxComplexSignatureHasApplicabilityError.tsx"
 Mismatch: "compiler/jsxEmptyExpressionNotCountedAsChild.tsx"
-Mismatch: "compiler/sourceMapValidationClasses.ts"
 Mismatch: "compiler/styledComponentsInstantiaionLimitNotReached.ts"
 Mismatch: "compiler/tsxReactPropsInferenceSucceedsOnIntersections.tsx"