diff --git a/.prettierignore b/.prettierignore
new file mode 100644
index 0000000..565975d
--- /dev/null
+++ b/.prettierignore
@@ -0,0 +1 @@
+codegen/snippet-tests/output/*
diff --git a/codegen/snippet-tests/output/01_primitive_types.pkl.ts b/codegen/snippet-tests/output/01_primitive_types.pkl.ts
index f0d3018..abb010b 100644
--- a/codegen/snippet-tests/output/01_primitive_types.pkl.ts
+++ b/codegen/snippet-tests/output/01_primitive_types.pkl.ts
@@ -1,5 +1,7 @@
-// This file was generated by `pkl-typescript` from Pkl module `01-primitiveTypes`.
-// DO NOT EDIT.
+/* This file was generated by `pkl-typescript` from Pkl module `01-primitiveTypes`. */
+/* DO NOT EDIT! */
+/* istanbul ignore file */
+/* eslint-disable */
 import * as pklTypescript from "@pkl-community/pkl-typescript"
 
 // Ref: Module root.
diff --git a/codegen/snippet-tests/output/02_collections.pkl.ts b/codegen/snippet-tests/output/02_collections.pkl.ts
index a4100b9..6d782e3 100644
--- a/codegen/snippet-tests/output/02_collections.pkl.ts
+++ b/codegen/snippet-tests/output/02_collections.pkl.ts
@@ -1,5 +1,7 @@
-// This file was generated by `pkl-typescript` from Pkl module `02-collections`.
-// DO NOT EDIT.
+/* This file was generated by `pkl-typescript` from Pkl module `02-collections`. */
+/* DO NOT EDIT! */
+/* istanbul ignore file */
+/* eslint-disable */
 import * as pklTypescript from "@pkl-community/pkl-typescript"
 
 // Ref: Module root.
diff --git a/codegen/snippet-tests/output/03_nullables.pkl.ts b/codegen/snippet-tests/output/03_nullables.pkl.ts
index 7389329..33d086b 100644
--- a/codegen/snippet-tests/output/03_nullables.pkl.ts
+++ b/codegen/snippet-tests/output/03_nullables.pkl.ts
@@ -1,5 +1,7 @@
-// This file was generated by `pkl-typescript` from Pkl module `03-nullables`.
-// DO NOT EDIT.
+/* This file was generated by `pkl-typescript` from Pkl module `03-nullables`. */
+/* DO NOT EDIT! */
+/* istanbul ignore file */
+/* eslint-disable */
 import * as pklTypescript from "@pkl-community/pkl-typescript"
 
 // Ref: Module root.
diff --git a/codegen/snippet-tests/output/04_with_class.pkl.ts b/codegen/snippet-tests/output/04_with_class.pkl.ts
index faa9f85..6287388 100644
--- a/codegen/snippet-tests/output/04_with_class.pkl.ts
+++ b/codegen/snippet-tests/output/04_with_class.pkl.ts
@@ -1,5 +1,7 @@
-// This file was generated by `pkl-typescript` from Pkl module `04-withClass`.
-// DO NOT EDIT.
+/* This file was generated by `pkl-typescript` from Pkl module `04-withClass`. */
+/* DO NOT EDIT! */
+/* istanbul ignore file */
+/* eslint-disable */
 import * as pklTypescript from "@pkl-community/pkl-typescript"
 
 // Ref: Module root.
diff --git a/codegen/snippet-tests/output/05_with_pair.pkl.ts b/codegen/snippet-tests/output/05_with_pair.pkl.ts
index 4d594e4..2f5dcb4 100644
--- a/codegen/snippet-tests/output/05_with_pair.pkl.ts
+++ b/codegen/snippet-tests/output/05_with_pair.pkl.ts
@@ -1,5 +1,7 @@
-// This file was generated by `pkl-typescript` from Pkl module `05-withPair`.
-// DO NOT EDIT.
+/* This file was generated by `pkl-typescript` from Pkl module `05-withPair`. */
+/* DO NOT EDIT! */
+/* istanbul ignore file */
+/* eslint-disable */
 import * as pklTypescript from "@pkl-community/pkl-typescript"
 
 // Ref: Module root.
diff --git a/codegen/snippet-tests/output/06_with_type_alias.pkl.ts b/codegen/snippet-tests/output/06_with_type_alias.pkl.ts
index f39473c..f513f6a 100644
--- a/codegen/snippet-tests/output/06_with_type_alias.pkl.ts
+++ b/codegen/snippet-tests/output/06_with_type_alias.pkl.ts
@@ -1,5 +1,7 @@
-// This file was generated by `pkl-typescript` from Pkl module `06-withTypeAlias`.
-// DO NOT EDIT.
+/* This file was generated by `pkl-typescript` from Pkl module `06-withTypeAlias`. */
+/* DO NOT EDIT! */
+/* istanbul ignore file */
+/* eslint-disable */
 import * as pklTypescript from "@pkl-community/pkl-typescript"
 
 // Ref: Module root.
diff --git a/codegen/snippet-tests/output/07_literal_types.pkl.ts b/codegen/snippet-tests/output/07_literal_types.pkl.ts
index 3397f5c..273948b 100644
--- a/codegen/snippet-tests/output/07_literal_types.pkl.ts
+++ b/codegen/snippet-tests/output/07_literal_types.pkl.ts
@@ -1,5 +1,7 @@
-// This file was generated by `pkl-typescript` from Pkl module `07-literalTypes`.
-// DO NOT EDIT.
+/* This file was generated by `pkl-typescript` from Pkl module `07-literalTypes`. */
+/* DO NOT EDIT! */
+/* istanbul ignore file */
+/* eslint-disable */
 import * as pklTypescript from "@pkl-community/pkl-typescript"
 
 // Ref: Module root.
diff --git a/codegen/snippet-tests/output/08_with_union.pkl.ts b/codegen/snippet-tests/output/08_with_union.pkl.ts
index f40c5ff..853837b 100644
--- a/codegen/snippet-tests/output/08_with_union.pkl.ts
+++ b/codegen/snippet-tests/output/08_with_union.pkl.ts
@@ -1,5 +1,7 @@
-// This file was generated by `pkl-typescript` from Pkl module `08-withUnion`.
-// DO NOT EDIT.
+/* This file was generated by `pkl-typescript` from Pkl module `08-withUnion`. */
+/* DO NOT EDIT! */
+/* istanbul ignore file */
+/* eslint-disable */
 import * as pklTypescript from "@pkl-community/pkl-typescript"
 
 // Ref: Module root.
diff --git a/codegen/snippet-tests/output/09_custom_types.pkl.ts b/codegen/snippet-tests/output/09_custom_types.pkl.ts
index fe04c00..c5d056d 100644
--- a/codegen/snippet-tests/output/09_custom_types.pkl.ts
+++ b/codegen/snippet-tests/output/09_custom_types.pkl.ts
@@ -1,5 +1,7 @@
-// This file was generated by `pkl-typescript` from Pkl module `09-customTypes`.
-// DO NOT EDIT.
+/* This file was generated by `pkl-typescript` from Pkl module `09-customTypes`. */
+/* DO NOT EDIT! */
+/* istanbul ignore file */
+/* eslint-disable */
 import * as pklTypescript from "@pkl-community/pkl-typescript"
 
 // Ref: Module root.
diff --git a/codegen/snippet-tests/output/11_with_import.pkl.ts b/codegen/snippet-tests/output/11_with_import.pkl.ts
index f5162dd..fba56fd 100644
--- a/codegen/snippet-tests/output/11_with_import.pkl.ts
+++ b/codegen/snippet-tests/output/11_with_import.pkl.ts
@@ -1,5 +1,7 @@
-// This file was generated by `pkl-typescript` from Pkl module `11-withImport`.
-// DO NOT EDIT.
+/* This file was generated by `pkl-typescript` from Pkl module `11-withImport`. */
+/* DO NOT EDIT! */
+/* istanbul ignore file */
+/* eslint-disable */
 import * as pklTypescript from "@pkl-community/pkl-typescript"
 
 // Ref: Module root.
diff --git a/codegen/snippet-tests/output/n10_pkl_typescript_tests_named_module.pkl.ts b/codegen/snippet-tests/output/n10_pkl_typescript_tests_named_module.pkl.ts
index 130f3be..ddc1a8e 100644
--- a/codegen/snippet-tests/output/n10_pkl_typescript_tests_named_module.pkl.ts
+++ b/codegen/snippet-tests/output/n10_pkl_typescript_tests_named_module.pkl.ts
@@ -1,5 +1,7 @@
-// This file was generated by `pkl-typescript` from Pkl module `n10.pkl.typescript.tests.namedModule`.
-// DO NOT EDIT.
+/* This file was generated by `pkl-typescript` from Pkl module `n10.pkl.typescript.tests.namedModule`. */
+/* DO NOT EDIT! */
+/* istanbul ignore file */
+/* eslint-disable */
 import * as pklTypescript from "@pkl-community/pkl-typescript"
 
 // Ref: Module root.
diff --git a/codegen/snippet-tests/output/n12_pkl_typescript_tests_module_name_override.pkl.ts b/codegen/snippet-tests/output/n12_pkl_typescript_tests_module_name_override.pkl.ts
index 2100986..5104593 100644
--- a/codegen/snippet-tests/output/n12_pkl_typescript_tests_module_name_override.pkl.ts
+++ b/codegen/snippet-tests/output/n12_pkl_typescript_tests_module_name_override.pkl.ts
@@ -1,5 +1,7 @@
-// This file was generated by `pkl-typescript` from Pkl module `n12.pkl.typescript.tests.moduleNameOverride`.
-// DO NOT EDIT.
+/* This file was generated by `pkl-typescript` from Pkl module `n12.pkl.typescript.tests.moduleNameOverride`. */
+/* DO NOT EDIT! */
+/* istanbul ignore file */
+/* eslint-disable */
 import * as pklTypescript from "@pkl-community/pkl-typescript"
 
 // Ref: Module root.
diff --git a/codegen/src/internal/TypescriptModule.pkl b/codegen/src/internal/TypescriptModule.pkl
index 52e27be..02442bb 100644
--- a/codegen/src/internal/TypescriptModule.pkl
+++ b/codegen/src/internal/TypescriptModule.pkl
@@ -69,8 +69,10 @@ local imports = generated
 
 contents: String = new Listing {
   """
-  // This file was generated by `pkl-typescript` from Pkl module `\(`module`.moduleClass.enclosingDeclaration.name)`.
-  // DO NOT EDIT.
+  /* This file was generated by `pkl-typescript` from Pkl module `\(`module`.moduleClass.enclosingDeclaration.name)`. */
+  /* DO NOT EDIT! */
+  /* istanbul ignore file */
+  /* eslint-disable */
   """
 
   utils.renderImports(imports)