diff --git a/modules/openapi-generator/src/main/resources/dart-dio/pubspec.mustache b/modules/openapi-generator/src/main/resources/dart-dio/pubspec.mustache
index 42f24a05c2b..8aea662a61a 100644
--- a/modules/openapi-generator/src/main/resources/dart-dio/pubspec.mustache
+++ b/modules/openapi-generator/src/main/resources/dart-dio/pubspec.mustache
@@ -2,16 +2,16 @@ name: {{pubName}}
 version: {{pubVersion}}
 description: {{pubDescription}}
 environment:
-    sdk: ">=2.7.0 <3.0.0"
+    sdk: '>=2.7.0 <3.0.0'
 dependencies:
     dio: ^3.0.9
-    built_value: ">=7.1.0 <9.0.0"
-    built_collection: ">=4.3.2 <6.0.0"
+    built_value: '>=7.1.0 <8.0.0'
+    built_collection: '>=4.3.2 <5.0.0'
 {{#timeMachine}}
     time_machine: ^0.9.12
 {{/timeMachine}}
 dev_dependencies:
-    built_value_generator: ">=7.1.0 <9.0.0"
+    built_value_generator: '>=7.1.0 <8.0.0'
     build_runner: ^1.7.1
-    test: ">=1.3.0 <1.16.0"
+    test: '>=1.3.0 <1.16.0'
 
diff --git a/samples/client/petstore/dart-dio/petstore_client_lib/pubspec.yaml b/samples/client/petstore/dart-dio/petstore_client_lib/pubspec.yaml
index f45f5e128cc..cd7cef8cc4f 100644
--- a/samples/client/petstore/dart-dio/petstore_client_lib/pubspec.yaml
+++ b/samples/client/petstore/dart-dio/petstore_client_lib/pubspec.yaml
@@ -2,13 +2,13 @@ name: openapi
 version: 1.0.0
 description: OpenAPI API client
 environment:
-    sdk: ">=2.7.0 <3.0.0"
+    sdk: '>=2.7.0 <3.0.0'
 dependencies:
     dio: ^3.0.9
-    built_value: ">=7.1.0 <9.0.0"
-    built_collection: ">=4.3.2 <6.0.0"
+    built_value: '>=7.1.0 <8.0.0'
+    built_collection: '>=4.3.2 <5.0.0'
 dev_dependencies:
-    built_value_generator: ">=7.1.0 <9.0.0"
+    built_value_generator: '>=7.1.0 <8.0.0'
     build_runner: ^1.7.1
-    test: ">=1.3.0 <1.16.0"
+    test: '>=1.3.0 <1.16.0'
 
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib/pubspec.yaml b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib/pubspec.yaml
index f45f5e128cc..cd7cef8cc4f 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib/pubspec.yaml
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib/pubspec.yaml
@@ -2,13 +2,13 @@ name: openapi
 version: 1.0.0
 description: OpenAPI API client
 environment:
-    sdk: ">=2.7.0 <3.0.0"
+    sdk: '>=2.7.0 <3.0.0'
 dependencies:
     dio: ^3.0.9
-    built_value: ">=7.1.0 <9.0.0"
-    built_collection: ">=4.3.2 <6.0.0"
+    built_value: '>=7.1.0 <8.0.0'
+    built_collection: '>=4.3.2 <5.0.0'
 dev_dependencies:
-    built_value_generator: ">=7.1.0 <9.0.0"
+    built_value_generator: '>=7.1.0 <8.0.0'
     build_runner: ^1.7.1
-    test: ">=1.3.0 <1.16.0"
+    test: '>=1.3.0 <1.16.0'
 
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake/pubspec.yaml b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake/pubspec.yaml
index f45f5e128cc..cd7cef8cc4f 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake/pubspec.yaml
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake/pubspec.yaml
@@ -2,13 +2,13 @@ name: openapi
 version: 1.0.0
 description: OpenAPI API client
 environment:
-    sdk: ">=2.7.0 <3.0.0"
+    sdk: '>=2.7.0 <3.0.0'
 dependencies:
     dio: ^3.0.9
-    built_value: ">=7.1.0 <9.0.0"
-    built_collection: ">=4.3.2 <6.0.0"
+    built_value: '>=7.1.0 <8.0.0'
+    built_collection: '>=4.3.2 <5.0.0'
 dev_dependencies:
-    built_value_generator: ">=7.1.0 <9.0.0"
+    built_value_generator: '>=7.1.0 <8.0.0'
     build_runner: ^1.7.1
-    test: ">=1.3.0 <1.16.0"
+    test: '>=1.3.0 <1.16.0'
 
diff --git a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake_tests/pubspec.yaml b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake_tests/pubspec.yaml
index 33a734cd053..0bf2e1272b0 100644
--- a/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake_tests/pubspec.yaml
+++ b/samples/openapi3/client/petstore/dart-dio/petstore_client_lib_fake_tests/pubspec.yaml
@@ -6,8 +6,8 @@ environment:
   sdk: ">=2.10.0 <3.0.0"
 
 dev_dependencies:
-  built_collection: ">=4.3.2 <6.0.0"
-  built_value: ">=7.1.0 <9.0.0"
+  built_collection: ">=4.3.2 <5.0.0"
+  built_value: ">=7.1.0 <8.0.0"
   dio: 3.0.10
 #  http_mock_adapter: 0.1.5
   http_mock_adapter: