diff --git a/crates/oxc_isolated_declarations/src/lib.rs b/crates/oxc_isolated_declarations/src/lib.rs
index c6ce19847..28b2f25f1 100644
--- a/crates/oxc_isolated_declarations/src/lib.rs
+++ b/crates/oxc_isolated_declarations/src/lib.rs
@@ -314,6 +314,9 @@ impl<'a> IsolatedDeclarations<'a> {
                         new_ast_stmts.push(Statement::ImportDeclaration(decl));
                     }
                 }
+                Statement::TSModuleDeclaration(decl) => {
+                    new_ast_stmts.push(Statement::TSModuleDeclaration(decl));
+                }
                 _ => {}
             }
         }
diff --git a/crates/oxc_isolated_declarations/tests/fixtures/module-declaration.ts b/crates/oxc_isolated_declarations/tests/fixtures/module-declaration.ts
new file mode 100644
index 000000000..ce062696a
--- /dev/null
+++ b/crates/oxc_isolated_declarations/tests/fixtures/module-declaration.ts
@@ -0,0 +1,5 @@
+import 'foo';
+declare module 'foo' {
+    interface Foo {}
+    const foo = 42;
+}
\ No newline at end of file
diff --git a/crates/oxc_isolated_declarations/tests/snapshots/module-declaration.snap b/crates/oxc_isolated_declarations/tests/snapshots/module-declaration.snap
new file mode 100644
index 000000000..05c4731df
--- /dev/null
+++ b/crates/oxc_isolated_declarations/tests/snapshots/module-declaration.snap
@@ -0,0 +1,12 @@
+---
+source: crates/oxc_isolated_declarations/tests/mod.rs
+input_file: crates/oxc_isolated_declarations/tests/fixtures/module-declaration.ts
+---
+==================== .D.TS ====================
+
+import "foo";
+declare module "foo" {
+	interface Foo {}
+	const foo = 42;
+}
+export {};