diff --git a/crates/fayalite/src/firrtl.rs b/crates/fayalite/src/firrtl.rs
index e1c9c5e..13f211f 100644
--- a/crates/fayalite/src/firrtl.rs
+++ b/crates/fayalite/src/firrtl.rs
@@ -2616,7 +2616,7 @@ pub struct ExportOptionsPrivate(());
 pub struct ExportOptions {
     #[clap(long = "no-simplify-memories", action = clap::ArgAction::SetFalse)]
     pub simplify_memories: bool,
-    #[clap(long, value_parser = OptionSimplifyEnumsKindValueParser, default_value = OptionSimplifyEnumsKindValueParser::NONE_NAME)]
+    #[clap(long, value_parser = OptionSimplifyEnumsKindValueParser, default_value = "replace-with-bundle-of-uints")]
     pub simplify_enums: std::option::Option<SimplifyEnumsKind>,
     #[doc(hidden)]
     #[clap(skip = ExportOptionsPrivate(()))]
@@ -2688,7 +2688,7 @@ impl Default for ExportOptions {
     fn default() -> Self {
         Self {
             simplify_memories: true,
-            simplify_enums: None,
+            simplify_enums: Some(SimplifyEnumsKind::ReplaceWithBundleOfUInts),
             __private: ExportOptionsPrivate(()),
         }
     }
diff --git a/crates/fayalite/tests/module.rs b/crates/fayalite/tests/module.rs
index 9927d69..b4998da 100644
--- a/crates/fayalite/tests/module.rs
+++ b/crates/fayalite/tests/module.rs
@@ -1,11 +1,8 @@
 // SPDX-License-Identifier: LGPL-3.0-or-later
 // See Notices.txt for copyright information
 use fayalite::{
-    annotations::CustomFirrtlAnnotation,
-    assert_export_firrtl,
-    intern::Intern,
-    module::transform::simplify_enums::{simplify_enums, SimplifyEnumsKind},
-    prelude::*,
+    annotations::CustomFirrtlAnnotation, assert_export_firrtl, firrtl::ExportOptions,
+    intern::Intern, module::transform::simplify_enums::SimplifyEnumsKind, prelude::*,
     ty::StaticType,
 };
 use serde_json::json;
@@ -86,6 +83,10 @@ fn test_mymodule() {
     #[rustfmt::skip] // work around https://github.com/rust-lang/rustfmt/issues/6161
     assert_export_firrtl! {
         m =>
+        options: ExportOptions {
+            simplify_enums: None,
+            ..ExportOptions::default()
+        },
         "/test/my_module.fir": r"FIRRTL version 3.2.0
 circuit my_module:
     type Ty0 = {`0`: UInt<32>, `1`: SInt<5>}
@@ -481,6 +482,10 @@ fn test_enum_literals() {
     #[rustfmt::skip] // work around https://github.com/rust-lang/rustfmt/issues/6161
     assert_export_firrtl! {
         m =>
+        options: ExportOptions {
+            simplify_enums: None,
+            ..ExportOptions::default()
+        },
         "/test/check_enum_literals.fir": r"FIRRTL version 3.2.0
 circuit check_enum_literals:
     type Ty0 = {|HdlNone, HdlSome: UInt<8>|}
@@ -502,12 +507,13 @@ circuit check_enum_literals:
             connect o2, {|A, B: UInt<8>, C: UInt<1>[3]|}(C, _array_literal_expr) @[module-XXXXXXXXXX.rs 10:1]
 ",
     };
-    let orig_m = m.canonical().intern();
-    let m = simplify_enums(orig_m, SimplifyEnumsKind::SimplifyToEnumsWithNoBody).unwrap();
-    dbg!(m);
     #[rustfmt::skip] // work around https://github.com/rust-lang/rustfmt/issues/6161
     assert_export_firrtl! {
         m =>
+        options: ExportOptions {
+            simplify_enums: Some(SimplifyEnumsKind::SimplifyToEnumsWithNoBody),
+            ..ExportOptions::default()
+        },
         "/test/check_enum_literals.fir": r"FIRRTL version 3.2.0
 circuit check_enum_literals:
     type Ty0 = {|HdlNone, HdlSome|}
@@ -549,11 +555,13 @@ circuit check_enum_literals:
             connect o2, _bundle_literal_expr_3 @[module-XXXXXXXXXX.rs 10:1]
 ",
     };
-    let m = simplify_enums(orig_m, SimplifyEnumsKind::ReplaceWithBundleOfUInts).unwrap();
-    dbg!(m);
     #[rustfmt::skip] // work around https://github.com/rust-lang/rustfmt/issues/6161
     assert_export_firrtl! {
         m =>
+        options: ExportOptions {
+            simplify_enums: Some(SimplifyEnumsKind::ReplaceWithBundleOfUInts),
+            ..ExportOptions::default()
+        },
         "/test/check_enum_literals.fir": r"FIRRTL version 3.2.0
 circuit check_enum_literals:
     type Ty0 = {tag: UInt<1>, body: UInt<8>}
@@ -593,11 +601,13 @@ circuit check_enum_literals:
             connect o2, _bundle_literal_expr_3 @[module-XXXXXXXXXX.rs 10:1]
 ",
     };
-    let m = simplify_enums(orig_m, SimplifyEnumsKind::ReplaceWithUInt).unwrap();
-    dbg!(m);
     #[rustfmt::skip] // work around https://github.com/rust-lang/rustfmt/issues/6161
     assert_export_firrtl! {
         m =>
+        options: ExportOptions {
+            simplify_enums: Some(SimplifyEnumsKind::ReplaceWithUInt),
+            ..ExportOptions::default()
+        },
         "/test/check_enum_literals.fir": r"FIRRTL version 3.2.0
 circuit check_enum_literals:
     type Ty0 = {tag: UInt<1>, body: UInt<8>}
@@ -708,6 +718,10 @@ fn test_struct_enum_match() {
     #[rustfmt::skip] // work around https://github.com/rust-lang/rustfmt/issues/6161
     assert_export_firrtl! {
         m =>
+        options: ExportOptions {
+            simplify_enums: None,
+            ..ExportOptions::default()
+        },
         "/test/check_struct_enum_match.fir": r"FIRRTL version 3.2.0
 circuit check_struct_enum_match:
     type Ty0 = {|HdlNone, HdlSome: UInt<8>|}
@@ -764,12 +778,13 @@ circuit check_struct_enum_match:
                 connect o[4], _match_arm_value_9[2] @[module-XXXXXXXXXX.rs 24:1]
 ",
     };
-    let orig_m = m.canonical().intern();
-    let m = simplify_enums(orig_m, SimplifyEnumsKind::SimplifyToEnumsWithNoBody).unwrap();
-    dbg!(m);
     #[rustfmt::skip] // work around https://github.com/rust-lang/rustfmt/issues/6161
     assert_export_firrtl! {
         m =>
+        options: ExportOptions {
+            simplify_enums: Some(SimplifyEnumsKind::SimplifyToEnumsWithNoBody),
+            ..ExportOptions::default()
+        },
         "/test/check_struct_enum_match.fir": r"FIRRTL version 3.2.0
 circuit check_struct_enum_match:
     type Ty0 = {|HdlNone, HdlSome|}
@@ -844,11 +859,13 @@ circuit check_struct_enum_match:
                 connect o[4], _cast_bits_to_array_expr_1[2] @[module-XXXXXXXXXX.rs 24:1]
 ",
     };
-    let m = simplify_enums(orig_m, SimplifyEnumsKind::ReplaceWithBundleOfUInts).unwrap();
-    dbg!(m);
     #[rustfmt::skip] // work around https://github.com/rust-lang/rustfmt/issues/6161
     assert_export_firrtl! {
         m =>
+        options: ExportOptions {
+            simplify_enums: Some(SimplifyEnumsKind::ReplaceWithBundleOfUInts),
+            ..ExportOptions::default()
+        },
         "/test/check_struct_enum_match.fir": r"FIRRTL version 3.2.0
 circuit check_struct_enum_match:
     type Ty0 = {tag: UInt<1>, body: UInt<8>}
@@ -915,11 +932,13 @@ circuit check_struct_enum_match:
             connect o[4], _cast_bits_to_array_expr_1[2] @[module-XXXXXXXXXX.rs 24:1]
 ",
     };
-    let m = simplify_enums(orig_m, SimplifyEnumsKind::ReplaceWithUInt).unwrap();
-    dbg!(m);
     #[rustfmt::skip] // work around https://github.com/rust-lang/rustfmt/issues/6161
     assert_export_firrtl! {
         m =>
+        options: ExportOptions {
+            simplify_enums: Some(SimplifyEnumsKind::ReplaceWithUInt),
+            ..ExportOptions::default()
+        },
         "/test/check_struct_enum_match.fir": r"FIRRTL version 3.2.0
 circuit check_struct_enum_match:
     module check_struct_enum_match: @[module-XXXXXXXXXX.rs 1:1]
@@ -2419,6 +2438,10 @@ fn test_memory_of_enum() {
     #[rustfmt::skip] // work around https://github.com/rust-lang/rustfmt/issues/6161
     assert_export_firrtl! {
         m =>
+        options: ExportOptions {
+            simplify_enums: None,
+            ..ExportOptions::default()
+        },
         "/test/check_memory_of_enum.fir": r#"FIRRTL version 3.2.0
 circuit check_memory_of_enum: %[[
   {
@@ -2524,12 +2547,13 @@ circuit check_memory_of_enum: %[[
 0000111101
 ",
     };
-    let orig_m = m.canonical().intern();
-    let m = simplify_enums(orig_m, SimplifyEnumsKind::SimplifyToEnumsWithNoBody).unwrap();
-    dbg!(m);
     #[rustfmt::skip] // work around https://github.com/rust-lang/rustfmt/issues/6161
     assert_export_firrtl! {
         m =>
+        options: ExportOptions {
+            simplify_enums: Some(SimplifyEnumsKind::SimplifyToEnumsWithNoBody),
+            ..ExportOptions::default()
+        },
         "/test/check_memory_of_enum.fir": r#"FIRRTL version 3.2.0
 circuit check_memory_of_enum: %[[
   {
@@ -2671,11 +2695,12 @@ circuit check_memory_of_enum: %[[
 01
 ",
     };
-    let m = simplify_enums(orig_m, SimplifyEnumsKind::ReplaceWithBundleOfUInts).unwrap();
-    dbg!(m);
     #[rustfmt::skip] // work around https://github.com/rust-lang/rustfmt/issues/6161
     assert_export_firrtl! {
         m =>
+        options: ExportOptions {
+            ..ExportOptions::default()
+        },
         "/test/check_memory_of_enum.fir": r#"FIRRTL version 3.2.0
 circuit check_memory_of_enum: %[[
   {
@@ -2801,11 +2826,13 @@ circuit check_memory_of_enum: %[[
 01
 ",
     };
-    let m = simplify_enums(orig_m, SimplifyEnumsKind::ReplaceWithUInt).unwrap();
-    dbg!(m);
     #[rustfmt::skip] // work around https://github.com/rust-lang/rustfmt/issues/6161
     assert_export_firrtl! {
         m =>
+        options: ExportOptions {
+            simplify_enums: Some(SimplifyEnumsKind::ReplaceWithUInt),
+            ..ExportOptions::default()
+        },
         "/test/check_memory_of_enum.fir": r#"FIRRTL version 3.2.0
 circuit check_memory_of_enum: %[[
   {
@@ -2906,6 +2933,10 @@ fn test_memory_of_array_of_enum() {
     #[rustfmt::skip] // work around https://github.com/rust-lang/rustfmt/issues/6161
     assert_export_firrtl! {
         m =>
+        options: ExportOptions {
+            simplify_enums: None,
+            ..ExportOptions::default()
+        },
         "/test/check_memory_of_array_of_enum.fir": r"FIRRTL version 3.2.0
 circuit check_memory_of_array_of_enum:
     type Ty0 = {|A, B: UInt<8>, C: UInt<1>[3]|}
@@ -3227,6 +3258,10 @@ circuit check_uninit:
     #[rustfmt::skip] // work around https://github.com/rust-lang/rustfmt/issues/6161
     assert_export_firrtl! {
         m =>
+        options: ExportOptions {
+            simplify_enums: None,
+            ..ExportOptions::default()
+        },
         "/test/check_uninit_1.fir": r"FIRRTL version 3.2.0
 circuit check_uninit_1:
     type Ty0 = {}
@@ -3329,6 +3364,10 @@ fn test_enum_connect_any() {
     #[rustfmt::skip] // work around https://github.com/rust-lang/rustfmt/issues/6161
     assert_export_firrtl! {
         m =>
+        options: ExportOptions {
+            simplify_enums: None,
+            ..ExportOptions::default()
+        },
         "/test/check_enum_connect_any.fir": r"FIRRTL version 3.2.0
 circuit check_enum_connect_any:
     type Ty0 = {|HdlNone, HdlSome: SInt<1>|}
@@ -3357,12 +3396,13 @@ circuit check_enum_connect_any:
             connect o2, i2 @[module-XXXXXXXXXX.rs 11:1]
 ",
     };
-    let orig_m = m.canonical().intern();
-    let m = simplify_enums(orig_m, SimplifyEnumsKind::SimplifyToEnumsWithNoBody).unwrap();
-    dbg!(m);
     #[rustfmt::skip] // work around https://github.com/rust-lang/rustfmt/issues/6161
     assert_export_firrtl! {
         m =>
+        options: ExportOptions {
+            simplify_enums: Some(SimplifyEnumsKind::SimplifyToEnumsWithNoBody),
+            ..ExportOptions::default()
+        },
         "/test/check_enum_connect_any.fir": r"FIRRTL version 3.2.0
 circuit check_enum_connect_any:
     type Ty0 = {|A, B, C|}
@@ -3577,11 +3617,13 @@ circuit check_enum_connect_any:
             connect o2, i2 @[module-XXXXXXXXXX.rs 11:1]
 ",
     };
-    let m = simplify_enums(orig_m, SimplifyEnumsKind::ReplaceWithBundleOfUInts).unwrap();
-    dbg!(m);
     #[rustfmt::skip] // work around https://github.com/rust-lang/rustfmt/issues/6161
     assert_export_firrtl! {
         m =>
+        options: ExportOptions {
+            simplify_enums: Some(SimplifyEnumsKind::ReplaceWithBundleOfUInts),
+            ..ExportOptions::default()
+        },
         "/test/check_enum_connect_any.fir": r"FIRRTL version 3.2.0
 circuit check_enum_connect_any:
     type Ty0 = {tag: UInt<2>, body: UInt<2>}
@@ -3732,12 +3774,14 @@ circuit check_enum_connect_any:
             connect o1, i1 @[module-XXXXXXXXXX.rs 10:1]
             connect o2, i2 @[module-XXXXXXXXXX.rs 11:1]
 ",
-    }
-    let m = simplify_enums(orig_m, SimplifyEnumsKind::ReplaceWithUInt).unwrap();
-    dbg!(m);
+    };
     #[rustfmt::skip] // work around https://github.com/rust-lang/rustfmt/issues/6161
     assert_export_firrtl! {
         m =>
+        options: ExportOptions {
+            simplify_enums: Some(SimplifyEnumsKind::ReplaceWithUInt),
+            ..ExportOptions::default()
+        },
         "/test/check_enum_connect_any.fir": r"FIRRTL version 3.2.0
 circuit check_enum_connect_any:
     type Ty0 = {tag: UInt<2>, body: UInt<2>}