diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java
index 1dc1cd8713b5..1d9d27eb4716 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java
@@ -225,7 +225,7 @@ apiTemplateFiles are for API outputs only (controllers/handlers).
     // How to encode special characters like $
     // They are translated to words like "Dollar" and prefixed with '
     // Then translated back during JSON encoding and decoding
-    protected Map<String, String> specialCharReplacements = new HashMap<>();
+    protected Map<String, String> specialCharReplacements = new LinkedHashMap<>();
     // When a model is an alias for a simple type
     protected Map<String, String> typeAliases = null;
     protected Boolean prependFormOrBodyParameters = false;
@@ -512,7 +512,7 @@ protected Map<String, Schema> getModelNameToSchemaCache() {
      * @return map of all models indexed by names
      */
     public Map<String, CodegenModel> getAllModels(Map<String, ModelsMap> objs) {
-        Map<String, CodegenModel> allModels = new HashMap<>();
+        Map<String, CodegenModel> allModels = new LinkedHashMap<>();
         for (Entry<String, ModelsMap> entry : objs.entrySet()) {
             String modelName = toModelName(entry.getKey());
             List<ModelMap> models = entry.getValue().getModels();
diff --git a/modules/openapi-generator/src/test/resources/3_0/protobuf-schema/pet.proto b/modules/openapi-generator/src/test/resources/3_0/protobuf-schema/pet.proto
index be5371035c98..3e85147a66d0 100644
--- a/modules/openapi-generator/src/test/resources/3_0/protobuf-schema/pet.proto
+++ b/modules/openapi-generator/src/test/resources/3_0/protobuf-schema/pet.proto
@@ -12,21 +12,18 @@ syntax = "proto3";
 
 package openapitools;
 
-import public "models/lizard_all_of.proto";
-import public "models/snake_all_of.proto";
 import public "models/cat_all_of.proto";
 import public "models/dog_all_of.proto";
+import public "models/lizard_all_of.proto";
 
 message Pet {
 
   string petType = 140636936;
 
-  bool hasLegs = 159828448;
-
-  bool lovesRocks = 499337491;
-
   string name = 3373707;
 
   string bark = 3016376;
 
+  bool lovesRocks = 499337491;
+
 }
diff --git a/samples/client/petstore/csharp/OpenAPIClient/src/Org.OpenAPITools/Model/Animal.cs b/samples/client/petstore/csharp/OpenAPIClient/src/Org.OpenAPITools/Model/Animal.cs
index e2578a131490..d06c695fa6ab 100644
--- a/samples/client/petstore/csharp/OpenAPIClient/src/Org.OpenAPITools/Model/Animal.cs
+++ b/samples/client/petstore/csharp/OpenAPIClient/src/Org.OpenAPITools/Model/Animal.cs
@@ -30,8 +30,8 @@ namespace Org.OpenAPITools.Model
     /// </summary>
     [DataContract]
     [JsonConverter(typeof(JsonSubtypes), "className")]
-    [JsonSubtypes.KnownSubType(typeof(Dog), "Dog")]
     [JsonSubtypes.KnownSubType(typeof(Cat), "Cat")]
+    [JsonSubtypes.KnownSubType(typeof(Dog), "Dog")]
     public partial class Animal :  IEquatable<Animal>, IValidatableObject
     {
         /// <summary>
diff --git a/samples/client/petstore/python-asyncio/petstore_api/models/animal.py b/samples/client/petstore/python-asyncio/petstore_api/models/animal.py
index eee29f37f881..335eb2625af4 100644
--- a/samples/client/petstore/python-asyncio/petstore_api/models/animal.py
+++ b/samples/client/petstore/python-asyncio/petstore_api/models/animal.py
@@ -46,9 +46,9 @@ class Animal(object):
     }
 
     discriminator_value_class_map = {
-        'Dog': 'Dog',
+        'BigCat': 'BigCat',
         'Cat': 'Cat',
-        'BigCat': 'BigCat'
+        'Dog': 'Dog'
     }
 
     def __init__(self, class_name=None, color='red', local_vars_configuration=None):  # noqa: E501
diff --git a/samples/client/petstore/python-legacy/petstore_api/models/animal.py b/samples/client/petstore/python-legacy/petstore_api/models/animal.py
index eee29f37f881..335eb2625af4 100644
--- a/samples/client/petstore/python-legacy/petstore_api/models/animal.py
+++ b/samples/client/petstore/python-legacy/petstore_api/models/animal.py
@@ -46,9 +46,9 @@ class Animal(object):
     }
 
     discriminator_value_class_map = {
-        'Dog': 'Dog',
+        'BigCat': 'BigCat',
         'Cat': 'Cat',
-        'BigCat': 'BigCat'
+        'Dog': 'Dog'
     }
 
     def __init__(self, class_name=None, color='red', local_vars_configuration=None):  # noqa: E501
diff --git a/samples/client/petstore/python-tornado/petstore_api/models/animal.py b/samples/client/petstore/python-tornado/petstore_api/models/animal.py
index eee29f37f881..335eb2625af4 100644
--- a/samples/client/petstore/python-tornado/petstore_api/models/animal.py
+++ b/samples/client/petstore/python-tornado/petstore_api/models/animal.py
@@ -46,9 +46,9 @@ class Animal(object):
     }
 
     discriminator_value_class_map = {
-        'Dog': 'Dog',
+        'BigCat': 'BigCat',
         'Cat': 'Cat',
-        'BigCat': 'BigCat'
+        'Dog': 'Dog'
     }
 
     def __init__(self, class_name=None, color='red', local_vars_configuration=None):  # noqa: E501
diff --git a/samples/openapi3/client/petstore/python-legacy/petstore_api/models/animal.py b/samples/openapi3/client/petstore/python-legacy/petstore_api/models/animal.py
index 1a36f3398fff..d4a49534078d 100755
--- a/samples/openapi3/client/petstore/python-legacy/petstore_api/models/animal.py
+++ b/samples/openapi3/client/petstore/python-legacy/petstore_api/models/animal.py
@@ -46,8 +46,8 @@ class Animal(object):
     }
 
     discriminator_value_class_map = {
-        'Dog': 'Dog',
-        'Cat': 'Cat'
+        'Cat': 'Cat',
+        'Dog': 'Dog'
     }
 
     def __init__(self, class_name=None, color='red', local_vars_configuration=None):  # noqa: E501
diff --git a/samples/server/petstore/haskell-servant/lib/OpenAPIPetstore/Types.hs b/samples/server/petstore/haskell-servant/lib/OpenAPIPetstore/Types.hs
index 9bb39c771ab6..7c19368f7c23 100644
--- a/samples/server/petstore/haskell-servant/lib/OpenAPIPetstore/Types.hs
+++ b/samples/server/petstore/haskell-servant/lib/OpenAPIPetstore/Types.hs
@@ -160,42 +160,42 @@ removeFieldLabelPrefix forParsing prefix =
   where
     replaceSpecialChars field = foldl (&) field (map mkCharReplacement specialChars)
     specialChars =
-      [ ("@", "'At")
-      , ("\\", "'Back_Slash")
-      , ("<=", "'Less_Than_Or_Equal_To")
-      , ("\"", "'Double_Quote")
-      , ("[", "'Left_Square_Bracket")
-      , ("]", "'Right_Square_Bracket")
+      [ ("$", "'Dollar")
       , ("^", "'Caret")
-      , ("_", "'Underscore")
-      , ("`", "'Backtick")
-      , ("!", "'Exclamation")
-      , ("#", "'Hash")
-      , ("$", "'Dollar")
-      , ("%", "'Percent")
-      , ("&", "'Ampersand")
-      , ("'", "'Quote")
-      , ("(", "'Left_Parenthesis")
-      , (")", "'Right_Parenthesis")
+      , ("|", "'Pipe")
+      , ("=", "'Equal")
       , ("*", "'Star")
-      , ("+", "'Plus")
-      , (",", "'Comma")
       , ("-", "'Dash")
-      , (".", "'Period")
-      , ("/", "'Slash")
+      , ("&", "'Ampersand")
+      , ("%", "'Percent")
+      , ("#", "'Hash")
+      , ("@", "'At")
+      , ("!", "'Exclamation")
+      , ("+", "'Plus")
       , (":", "'Colon")
       , (";", "'Semicolon")
-      , ("{", "'Left_Curly_Bracket")
-      , ("|", "'Pipe")
+      , (">", "'GreaterThan")
       , ("<", "'LessThan")
-      , ("!=", "'Not_Equal")
-      , ("=", "'Equal")
+      , (".", "'Period")
+      , ("_", "'Underscore")
+      , ("?", "'Question_Mark")
+      , (",", "'Comma")
+      , ("'", "'Quote")
+      , ("/", "'Slash")
+      , ("(", "'Left_Parenthesis")
+      , (")", "'Right_Parenthesis")
+      , ("{", "'Left_Curly_Bracket")
       , ("}", "'Right_Curly_Bracket")
-      , (">", "'GreaterThan")
+      , ("[", "'Left_Square_Bracket")
+      , ("]", "'Right_Square_Bracket")
       , ("~", "'Tilde")
-      , ("?", "'Question_Mark")
+      , ("`", "'Backtick")
+      , ("<=", "'Less_Than_Or_Equal_To")
       , (">=", "'Greater_Than_Or_Equal_To")
+      , ("!=", "'Not_Equal")
       , ("~=", "'Tilde_Equal")
+      , ("\\", "'Back_Slash")
+      , ("\"", "'Double_Quote")
       ]
     mkCharReplacement (replaceStr, searchStr) = T.unpack . replacer (T.pack searchStr) (T.pack replaceStr) . T.pack
     replacer =
diff --git a/samples/server/petstore/haskell-yesod/src/OpenAPIPetstore/Types.hs b/samples/server/petstore/haskell-yesod/src/OpenAPIPetstore/Types.hs
index 1ba7c5d14872..7057e0e55dac 100644
--- a/samples/server/petstore/haskell-yesod/src/OpenAPIPetstore/Types.hs
+++ b/samples/server/petstore/haskell-yesod/src/OpenAPIPetstore/Types.hs
@@ -130,42 +130,42 @@ removeFieldLabelPrefix forParsing prefix =
   where
     replaceSpecialChars field = foldl (&) field (map mkCharReplacement specialChars)
     specialChars =
-      [ ("@", "'At")
-      , ("\\", "'Back_Slash")
-      , ("<=", "'Less_Than_Or_Equal_To")
-      , ("\"", "'Double_Quote")
-      , ("[", "'Left_Square_Bracket")
-      , ("]", "'Right_Square_Bracket")
+      [ ("$", "'Dollar")
       , ("^", "'Caret")
-      , ("_", "'Underscore")
-      , ("`", "'Backtick")
-      , ("!", "'Exclamation")
-      , ("#", "'Hash")
-      , ("$", "'Dollar")
-      , ("%", "'Percent")
-      , ("&", "'Ampersand")
-      , ("'", "'Quote")
-      , ("(", "'Left_Parenthesis")
-      , (")", "'Right_Parenthesis")
+      , ("|", "'Pipe")
+      , ("=", "'Equal")
       , ("*", "'Star")
-      , ("+", "'Plus")
-      , (",", "'Comma")
       , ("-", "'Dash")
-      , (".", "'Period")
-      , ("/", "'Slash")
+      , ("&", "'Ampersand")
+      , ("%", "'Percent")
+      , ("#", "'Hash")
+      , ("@", "'At")
+      , ("!", "'Exclamation")
+      , ("+", "'Plus")
       , (":", "'Colon")
       , (";", "'Semicolon")
-      , ("{", "'Left_Curly_Bracket")
-      , ("|", "'Pipe")
+      , (">", "'GreaterThan")
       , ("<", "'LessThan")
-      , ("!=", "'Not_Equal")
-      , ("=", "'Equal")
+      , (".", "'Period")
+      , ("_", "'Underscore")
+      , ("?", "'Question_Mark")
+      , (",", "'Comma")
+      , ("'", "'Quote")
+      , ("/", "'Slash")
+      , ("(", "'Left_Parenthesis")
+      , (")", "'Right_Parenthesis")
+      , ("{", "'Left_Curly_Bracket")
       , ("}", "'Right_Curly_Bracket")
-      , (">", "'GreaterThan")
+      , ("[", "'Left_Square_Bracket")
+      , ("]", "'Right_Square_Bracket")
       , ("~", "'Tilde")
-      , ("?", "'Question_Mark")
+      , ("`", "'Backtick")
+      , ("<=", "'Less_Than_Or_Equal_To")
       , (">=", "'Greater_Than_Or_Equal_To")
+      , ("!=", "'Not_Equal")
       , ("~=", "'Tilde_Equal")
+      , ("\\", "'Back_Slash")
+      , ("\"", "'Double_Quote")
       ]
     mkCharReplacement (replaceStr, searchStr) = T.unpack . replacer (T.pack searchStr) (T.pack replaceStr) . T.pack
     replacer =