diff --git a/example/pubspec.lock b/example/pubspec.lock
index 6f3069f..bafa06f 100644
--- a/example/pubspec.lock
+++ b/example/pubspec.lock
@@ -5,18 +5,18 @@ packages:
     dependency: transitive
     description:
       name: async
-      sha256: "947bfcf187f74dbc5e146c9eb9c0f10c9f8b30743e341481c1e2ed3ecc18c20c"
+      sha256: d2872f9c19731c2e5f10444b14686eb7cc85c76274bd6c16e1816bff9a3bab63
       url: "https://pub.dev"
     source: hosted
-    version: "2.11.0"
+    version: "2.12.0"
   boolean_selector:
     dependency: transitive
     description:
       name: boolean_selector
-      sha256: "6cfb5af12253eaf2b368f07bacc5a80d1301a071c73360d746b7f2e32d762c66"
+      sha256: "8aab1771e1243a5063b8b0ff68042d67334e3feab9e95b9490f9a6ebf73b42ea"
       url: "https://pub.dev"
     source: hosted
-    version: "2.1.1"
+    version: "2.1.2"
   characters:
     dependency: transitive
     description:
@@ -44,23 +44,23 @@ packages:
       path: ".."
       relative: true
     source: path
-    version: "5.0.0+20"
+    version: "7.0.0"
   flutter_lints:
     dependency: "direct dev"
     description:
       name: flutter_lints
-      sha256: aeb0b80a8b3709709c9cc496cdc027c5b3216796bc0af0ce1007eaf24464fd4c
+      sha256: a25a15ebbdfc33ab1cd26c63a6ee519df92338a9c10f122adda92938253bef04
       url: "https://pub.dev"
     source: hosted
-    version: "2.0.1"
+    version: "2.0.3"
   functional_listener:
     dependency: "direct main"
     description:
       name: functional_listener
-      sha256: ee8ffc29b2448981d96addf44ac9b4af2ba4ca2627979e77d3e6fe59b967ca4f
+      sha256: c096db771b4ce7ba0f886cc4a761044b11e8276a7bc24cfc812dc4b2bc6f5b16
       url: "https://pub.dev"
     source: hosted
-    version: "3.0.0"
+    version: "4.1.0"
   http:
     dependency: "direct main"
     description:
@@ -81,18 +81,18 @@ packages:
     dependency: transitive
     description:
       name: lints
-      sha256: "5e4a9cd06d447758280a8ac2405101e0e2094d2a1dbdd3756aec3fe7775ba593"
+      sha256: "0a217c6c989d21039f1498c3ed9f3ed71b354e69873f13a8dfc3c9fe76f1b452"
       url: "https://pub.dev"
     source: hosted
-    version: "2.0.1"
+    version: "2.1.1"
   matcher:
     dependency: transitive
     description:
       name: matcher
-      sha256: "1803e76e6653768d64ed8ff2e1e67bea3ad4b923eb5c56a295c3e634bad5960e"
+      sha256: dc58c723c3c24bf8d3e2d3ad3f2f9d7bd9cf43ec6feaa64181775e60190153f2
       url: "https://pub.dev"
     source: hosted
-    version: "0.12.16"
+    version: "0.12.17"
   material_color_utilities:
     dependency: transitive
     description:
@@ -113,18 +113,18 @@ packages:
     dependency: transitive
     description:
       name: path
-      sha256: "8829d8a55c13fc0e37127c29fedf290c102f4e40ae94ada574091fe0ff96c917"
+      sha256: "75cca69d1490965be98c73ceaea117e8a04dd21217b37b292c9ddbec0d955bc5"
       url: "https://pub.dev"
     source: hosted
-    version: "1.8.3"
+    version: "1.9.1"
   quiver:
     dependency: transitive
     description:
       name: quiver
-      sha256: b1c1ac5ce6688d77f65f3375a9abb9319b3cb32486bdc7a1e0fdf004d7ba4e47
+      sha256: ea0b925899e64ecdfbf9c7becb60d5b50e706ade44a85b2363be2a22d88117d2
       url: "https://pub.dev"
     source: hosted
-    version: "3.2.1"
+    version: "3.2.2"
   sky_engine:
     dependency: transitive
     description: flutter
@@ -142,26 +142,26 @@ packages:
     dependency: transitive
     description:
       name: stack_trace
-      sha256: c3c7d8edb15bee7f0f74debd4b9c5f3c2ea86766fe4178eb2a18eb30a0bdaed5
+      sha256: "9f47fd3630d76be3ab26f0ee06d213679aa425996925ff3feffdec504931c377"
       url: "https://pub.dev"
     source: hosted
-    version: "1.11.0"
+    version: "1.12.0"
   stream_channel:
     dependency: transitive
     description:
       name: stream_channel
-      sha256: "83615bee9045c1d322bbbd1ba209b7a749c2cbcdcb3fdd1df8eb488b3279c1c8"
+      sha256: ba2aa5d8cc609d96bbb2899c28934f9e1af5cddbd60a827822ea467161eb54e7
       url: "https://pub.dev"
     source: hosted
-    version: "2.1.1"
+    version: "2.1.2"
   string_scanner:
     dependency: transitive
     description:
       name: string_scanner
-      sha256: "556692adab6cfa87322a115640c11f13cb77b3f076ddcc5d6ae3c20242bedcde"
+      sha256: "0bd04f5bb74fcd6ff0606a888a30e917af9bd52820b178eaa464beb11dca84b6"
       url: "https://pub.dev"
     source: hosted
-    version: "1.2.0"
+    version: "1.4.0"
   term_glyph:
     dependency: transitive
     description:
@@ -174,10 +174,10 @@ packages:
     dependency: transitive
     description:
       name: test_api
-      sha256: "75760ffd7786fffdfb9597c35c5b27eaeec82be8edfb6d71d32651128ed7aab8"
+      sha256: "9955ae474176f7ac8ee4e989dadfb411a58c30415bcfb648fa04b2b8a03afa7f"
       url: "https://pub.dev"
     source: hosted
-    version: "0.6.0"
+    version: "0.7.0"
   typed_data:
     dependency: transitive
     description:
@@ -195,4 +195,4 @@ packages:
     source: hosted
     version: "2.1.4"
 sdks:
-  dart: ">=3.3.0-0 <4.0.0"
+  dart: ">=3.4.0 <4.0.0"
diff --git a/example_command_results/lib/homepage_command_builder.dart b/example_command_results/lib/homepage_command_builder.dart
index 5e49940..2a83da8 100644
--- a/example_command_results/lib/homepage_command_builder.dart
+++ b/example_command_results/lib/homepage_command_builder.dart
@@ -48,7 +48,7 @@ class _HomePageState extends State<HomePage> {
                 children: [
                   Text('An Error has occurred!'),
                   Text(error.toString()),
-                  if (error != null) Text('For search term: $param')
+                  Text('For search term: $param')
                 ],
               ),
             ),
diff --git a/lib/command_builder.dart b/lib/command_builder.dart
index d90034d..2271453 100644
--- a/lib/command_builder.dart
+++ b/lib/command_builder.dart
@@ -13,7 +13,7 @@ class CommandBuilder<TParam, TResult> extends StatelessWidget {
   )? whileExecuting;
   final Widget Function(
     BuildContext context,
-    Object?,
+    Object,
     TResult? lastValue,
     TParam?,
   )? onError;
@@ -62,10 +62,10 @@ extension ToWidgeCommandResult<TParam, TResult>
     required Widget Function(TResult result, TParam? param) onData,
     Widget Function(TParam? param)? onNullData,
     Widget Function(TResult? lastResult, TParam? param)? whileExecuting,
-    Widget Function(Object? error, TResult? lastResult, TParam? param)? onError,
+    Widget Function(Object error, TResult? lastResult, TParam? param)? onError,
   }) {
     if (error != null) {
-      return onError?.call(error, data, paramData) ?? const SizedBox();
+      return onError?.call(error!, data, paramData) ?? const SizedBox();
     }
     if (isExecuting) {
       return whileExecuting?.call(data, paramData) ?? const SizedBox();
diff --git a/pubspec.lock b/pubspec.lock
index fd19011..06032bb 100644
--- a/pubspec.lock
+++ b/pubspec.lock
@@ -5,26 +5,26 @@ packages:
     dependency: transitive
     description:
       name: _fe_analyzer_shared
-      sha256: ae92f5d747aee634b87f89d9946000c2de774be1d6ac3e58268224348cd0101a
+      sha256: "0b2f2bd91ba804e53a61d757b986f89f1f9eaed5b11e4b2f5a2468d86d6c9fc7"
       url: "https://pub.dev"
     source: hosted
-    version: "61.0.0"
+    version: "67.0.0"
   analyzer:
     dependency: transitive
     description:
       name: analyzer
-      sha256: ea3d8652bda62982addfd92fdc2d0214e5f82e43325104990d4f4c4a2a313562
+      sha256: "37577842a27e4338429a1cbc32679d508836510b056f1eedf0c8d20e39c1383d"
       url: "https://pub.dev"
     source: hosted
-    version: "5.13.0"
+    version: "6.4.1"
   args:
     dependency: transitive
     description:
       name: args
-      sha256: eef6c46b622e0494a36c5a12d10d77fb4e855501a91c1b9ef9339326e58f0596
+      sha256: bf9f5caeea8d8fe6721a9c358dd8a5c1947b27f1cfaa18b39c301273594919e6
       url: "https://pub.dev"
     source: hosted
-    version: "2.4.2"
+    version: "2.6.0"
   async:
     dependency: transitive
     description:
@@ -69,26 +69,26 @@ packages:
     dependency: transitive
     description:
       name: convert
-      sha256: "0f08b14755d163f6e2134cb58222dd25ea2a2ee8a195e53983d57c075324d592"
+      sha256: b30acd5944035672bc15c6b7a8b47d773e41e2f17de064350988c5d02adb1c68
       url: "https://pub.dev"
     source: hosted
-    version: "3.1.1"
+    version: "3.1.2"
   coverage:
     dependency: transitive
     description:
       name: coverage
-      sha256: "3945034e86ea203af7a056d98e98e42a5518fff200d6e8e6647e1886b07e936e"
+      sha256: "4b03e11f6d5b8f6e5bb5e9f7889a56fe6c5cbe942da5378ea4d4d7f73ef9dfe5"
       url: "https://pub.dev"
     source: hosted
-    version: "1.8.0"
+    version: "1.11.0"
   crypto:
     dependency: transitive
     description:
       name: crypto
-      sha256: ff625774173754681d66daaf4a448684fb04b78f902da9cb3d308c19cc5e8bab
+      sha256: "1e445881f28f22d6140f181e07737b22f1e099a5e1ff94b0af2f9e4a463f4855"
       url: "https://pub.dev"
     source: hosted
-    version: "3.0.3"
+    version: "3.0.6"
   fake_async:
     dependency: "direct dev"
     description:
@@ -101,10 +101,10 @@ packages:
     dependency: transitive
     description:
       name: file
-      sha256: "5fc22d7c25582e38ad9a8515372cd9a93834027aacf1801cf01164dac0ffa08c"
+      sha256: a3b4f84adafef897088c160faf7dfffb7696046cb13ae90b508c2cbc95d3b8d4
       url: "https://pub.dev"
     source: hosted
-    version: "7.0.0"
+    version: "7.0.1"
   flutter:
     dependency: "direct main"
     description: flutter
@@ -119,18 +119,18 @@ packages:
     dependency: transitive
     description:
       name: frontend_server_client
-      sha256: "408e3ca148b31c20282ad6f37ebfa6f4bdc8fede5b74bc2f08d9d92b55db3612"
+      sha256: f64a0333a82f30b0cca061bc3d143813a486dc086b574bfb233b7c1372427694
       url: "https://pub.dev"
     source: hosted
-    version: "3.2.0"
+    version: "4.0.0"
   functional_listener:
     dependency: "direct main"
     description:
       name: functional_listener
-      sha256: d65803c98a841a15957c426f183ea7f03b7de8fa4a6d1ab32ca2485584c3e3ef
+      sha256: c096db771b4ce7ba0f886cc4a761044b11e8276a7bc24cfc812dc4b2bc6f5b16
       url: "https://pub.dev"
     source: hosted
-    version: "4.0.0"
+    version: "4.1.0"
   glob:
     dependency: transitive
     description:
@@ -167,10 +167,10 @@ packages:
     dependency: transitive
     description:
       name: js
-      sha256: f2c445dce49627136094980615a031419f7f3eb393237e4ecd97ac15dea343f3
+      sha256: c1b2e9b5ea78c45e1a0788d29606ba27dc5f71f019f32ca5140f61ef071838cf
       url: "https://pub.dev"
     source: hosted
-    version: "0.6.7"
+    version: "0.7.1"
   leak_tracker:
     dependency: transitive
     description:
@@ -199,18 +199,18 @@ packages:
     dependency: "direct dev"
     description:
       name: lint
-      sha256: "03369e5af39b115ef89872b764ff1ac5e5858ab0227776d036d8fe43844221e8"
+      sha256: d758a5211fce7fd3f5e316f804daefecdc34c7e53559716125e6da7388ae8565
       url: "https://pub.dev"
     source: hosted
-    version: "2.0.20"
+    version: "2.3.0"
   logging:
     dependency: transitive
     description:
       name: logging
-      sha256: "623a88c9594aa774443aa3eb2d41807a48486b5613e67599fb4c41c0ad47c340"
+      sha256: c8245ada5f1717ed44271ed1c26b8ce85ca3228fd2ffdb75468ab01979309d61
       url: "https://pub.dev"
     source: hosted
-    version: "1.2.0"
+    version: "1.3.0"
   matcher:
     dependency: transitive
     description:
@@ -239,10 +239,10 @@ packages:
     dependency: transitive
     description:
       name: mime
-      sha256: e4ff8e8564c03f255408decd16e7899da1733852a9110a58fe6d1b817684a63e
+      sha256: "41a20518f0cb1256669420fdba0cd90d21561e560ac240f26ef8322e45bb7ed6"
       url: "https://pub.dev"
     source: hosted
-    version: "1.0.4"
+    version: "2.0.0"
   node_preamble:
     dependency: transitive
     description:
@@ -287,10 +287,10 @@ packages:
     dependency: "direct main"
     description:
       name: quiver
-      sha256: b1c1ac5ce6688d77f65f3375a9abb9319b3cb32486bdc7a1e0fdf004d7ba4e47
+      sha256: ea0b925899e64ecdfbf9c7becb60d5b50e706ade44a85b2363be2a22d88117d2
       url: "https://pub.dev"
     source: hosted
-    version: "3.2.1"
+    version: "3.2.2"
   shelf:
     dependency: transitive
     description:
@@ -311,10 +311,10 @@ packages:
     dependency: transitive
     description:
       name: shelf_static
-      sha256: a41d3f53c4adf0f57480578c1d61d90342cd617de7fc8077b1304643c2d85c1e
+      sha256: c87c3875f91262785dade62d135760c2c69cb217ac759485334c5857ad89f6e3
       url: "https://pub.dev"
     source: hosted
-    version: "1.1.2"
+    version: "1.1.3"
   shelf_web_socket:
     dependency: transitive
     description:
@@ -332,10 +332,10 @@ packages:
     dependency: transitive
     description:
       name: source_map_stack_trace
-      sha256: "84cf769ad83aa6bb61e0aa5a18e53aea683395f196a6f39c4c881fb90ed4f7ae"
+      sha256: c0713a43e323c3302c2abe2a1cc89aa057a387101ebd280371d6a6c9fa68516b
       url: "https://pub.dev"
     source: hosted
-    version: "2.1.1"
+    version: "2.1.2"
   source_maps:
     dependency: transitive
     description:
@@ -440,22 +440,30 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "1.1.0"
+  web:
+    dependency: transitive
+    description:
+      name: web
+      sha256: "97da13628db363c635202ad97068d47c5b8aa555808e7a9411963c533b449b27"
+      url: "https://pub.dev"
+    source: hosted
+    version: "0.5.1"
   web_socket_channel:
     dependency: transitive
     description:
       name: web_socket_channel
-      sha256: d88238e5eac9a42bb43ca4e721edba3c08c6354d4a53063afaa568516217621b
+      sha256: "58c6666b342a38816b2e7e50ed0f1e261959630becd4c879c4f26bfa14aa5a42"
       url: "https://pub.dev"
     source: hosted
-    version: "2.4.0"
+    version: "2.4.5"
   webkit_inspection_protocol:
     dependency: transitive
     description:
       name: webkit_inspection_protocol
-      sha256: "67d3a8b6c79e1987d19d848b0892e582dbb0c66c57cc1fef58a177dd2aa2823d"
+      sha256: "87d3f2333bb240704cd3f1c6b5b7acd8a10e7f0bc28c28dcf14e782014f4a572"
       url: "https://pub.dev"
     source: hosted
-    version: "1.2.0"
+    version: "1.2.1"
   yaml:
     dependency: transitive
     description:
@@ -465,5 +473,5 @@ packages:
     source: hosted
     version: "3.1.2"
 sdks:
-  dart: ">=3.3.0 <4.0.0"
+  dart: ">=3.4.0 <4.0.0"
   flutter: ">=3.18.0-18.0.pre.54"