diff --git a/AWSPolly/AWSPollyModel.h b/AWSPolly/AWSPollyModel.h
index 5a8e6975852..f8ef7ef5b07 100644
--- a/AWSPolly/AWSPollyModel.h
+++ b/AWSPolly/AWSPollyModel.h
@@ -50,6 +50,7 @@ typedef NS_ENUM(NSInteger, AWSPollyEngine) {
     AWSPollyEngineUnknown,
     AWSPollyEngineStandard,
     AWSPollyEngineNeural,
+    AWSPollyEngineLongForm,
 };
 
 typedef NS_ENUM(NSInteger, AWSPollyGender) {
@@ -226,6 +227,8 @@ typedef NS_ENUM(NSInteger, AWSPollyVoiceId) {
     AWSPollyVoiceIdLisa,
     AWSPollyVoiceIdIsabelle,
     AWSPollyVoiceIdZayd,
+    AWSPollyVoiceIdDanielle,
+    AWSPollyVoiceIdGregory,
 };
 
 @class AWSPollyDeleteLexiconInput;
@@ -280,7 +283,7 @@ typedef NS_ENUM(NSInteger, AWSPollyVoiceId) {
 
 
 /**
- <p>Specifies the engine (<code>standard</code> or <code>neural</code>) used by Amazon Polly when processing input text for speech synthesis. </p>
+ <p>Specifies the engine (<code>standard</code>, <code>neural</code> or <code>long-form</code>) used by Amazon Polly when processing input text for speech synthesis. </p>
  */
 @property (nonatomic, assign) AWSPollyEngine engine;
 
@@ -555,7 +558,7 @@ typedef NS_ENUM(NSInteger, AWSPollyVoiceId) {
 
 
 /**
- <p>Specifies the engine (<code>standard</code> or <code>neural</code>) for Amazon Polly to use when processing input text for speech synthesis. Using a voice that is not supported for the engine selected will result in an error.</p>
+ <p>Specifies the engine (<code>standard</code>, <code>neural</code> or <code>long-form</code>) for Amazon Polly to use when processing input text for speech synthesis. Using a voice that is not supported for the engine selected will result in an error.</p>
  */
 @property (nonatomic, assign) AWSPollyEngine engine;
 
@@ -585,7 +588,7 @@ typedef NS_ENUM(NSInteger, AWSPollyVoiceId) {
 @property (nonatomic, strong) NSString * _Nullable outputS3KeyPrefix;
 
 /**
- <p>The audio frequency specified in Hz.</p><p>The valid values for mp3 and ogg_vorbis are "8000", "16000", "22050", and "24000". The default value for standard voices is "22050". The default value for neural voices is "24000".</p><p>Valid values for pcm are "8000" and "16000" The default value is "16000". </p>
+ <p>The audio frequency specified in Hz.</p><p>The valid values for mp3 and ogg_vorbis are "8000", "16000", "22050", and "24000". The default value for standard voices is "22050". The default value for neural voices is "24000". The default value for long-form voices is "24000".</p><p>Valid values for pcm are "8000" and "16000" The default value is "16000". </p>
  */
 @property (nonatomic, strong) NSString * _Nullable sampleRate;
 
@@ -641,7 +644,7 @@ typedef NS_ENUM(NSInteger, AWSPollyVoiceId) {
 @property (nonatomic, strong) NSDate * _Nullable creationTime;
 
 /**
- <p>Specifies the engine (<code>standard</code> or <code>neural</code>) for Amazon Polly to use when processing input text for speech synthesis. Using a voice that is not supported for the engine selected will result in an error.</p>
+ <p>Specifies the engine (<code>standard</code>, <code>neural</code> or <code>long-form</code>) for Amazon Polly to use when processing input text for speech synthesis. Using a voice that is not supported for the engine selected will result in an error.</p>
  */
 @property (nonatomic, assign) AWSPollyEngine engine;
 
@@ -671,7 +674,7 @@ typedef NS_ENUM(NSInteger, AWSPollyVoiceId) {
 @property (nonatomic, strong) NSNumber * _Nullable requestCharacters;
 
 /**
- <p>The audio frequency specified in Hz.</p><p>The valid values for mp3 and ogg_vorbis are "8000", "16000", "22050", and "24000". The default value for standard voices is "22050". The default value for neural voices is "24000".</p><p>Valid values for pcm are "8000" and "16000" The default value is "16000". </p>
+ <p>The audio frequency specified in Hz.</p><p>The valid values for mp3 and ogg_vorbis are "8000", "16000", "22050", and "24000". The default value for standard voices is "22050". The default value for neural voices is "24000". The default value for long-form voices is "24000".</p><p>Valid values for pcm are "8000" and "16000" The default value is "16000". </p>
  */
 @property (nonatomic, strong) NSString * _Nullable sampleRate;
 
@@ -719,7 +722,7 @@ typedef NS_ENUM(NSInteger, AWSPollyVoiceId) {
 
 
 /**
- <p>Specifies the engine (<code>standard</code> or <code>neural</code>) for Amazon Polly to use when processing input text for speech synthesis. For information on Amazon Polly voices and which voices are available in standard-only, NTTS-only, and both standard and NTTS formats, see <a href="https://docs.aws.amazon.com/polly/latest/dg/voicelist.html">Available Voices</a>.</p><p><b>NTTS-only voices</b></p><p>When using NTTS-only voices such as Kevin (en-US), this parameter is required and must be set to <code>neural</code>. If the engine is not specified, or is set to <code>standard</code>, this will result in an error. </p><p>Type: String</p><p>Valid Values: <code>standard</code> | <code>neural</code></p><p>Required: Yes</p><p><b>Standard voices</b></p><p>For standard voices, this is not required; the engine parameter defaults to <code>standard</code>. If the engine is not specified, or is set to <code>standard</code> and an NTTS-only voice is selected, this will result in an error. </p>
+ <p>Specifies the engine (<code>standard</code>, <code>neural</code> or <code>long-form</code>) for Amazon Polly to use when processing input text for speech synthesis. For information on Amazon Polly voices and which voices are available for each engine, see <a href="https://docs.aws.amazon.com/polly/latest/dg/voicelist.html">Available Voices</a>.</p><p><b>NTTS-only voices</b></p><p>When using NTTS-only voices such as Kevin (en-US), this parameter is required and must be set to <code>neural</code>. If the engine is not specified, or is set to <code>standard</code>, this will result in an error. </p><p><b>long-form-only voices</b></p><p>When using long-form-only voices such as Danielle (en-US), this parameter is required and must be set to <code>long-form</code>. If the engine is not specified, or is set to <code>standard</code> or <code>neural</code>, this will result in an error. </p><p>Type: String</p><p>Valid Values: <code>standard</code> | <code>neural</code> | <code>long-form</code></p><p>Required: Yes</p><p><b>Standard voices</b></p><p>For standard voices, this is not required; the engine parameter defaults to <code>standard</code>. If the engine is not specified, or is set to <code>standard</code> and an NTTS-only voice is selected, this will result in an error. </p>
  */
 @property (nonatomic, assign) AWSPollyEngine engine;
 
@@ -739,7 +742,7 @@ typedef NS_ENUM(NSInteger, AWSPollyVoiceId) {
 @property (nonatomic, assign) AWSPollyOutputFormat outputFormat;
 
 /**
- <p>The audio frequency specified in Hz.</p><p>The valid values for mp3 and ogg_vorbis are "8000", "16000", "22050", and "24000". The default value for standard voices is "22050". The default value for neural voices is "24000".</p><p>Valid values for pcm are "8000" and "16000" The default value is "16000". </p>
+ <p>The audio frequency specified in Hz.</p><p>The valid values for mp3 and ogg_vorbis are "8000", "16000", "22050", and "24000". The default value for standard voices is "22050". The default value for neural voices is "24000". The default value for long-form voices is "24000".</p><p>Valid values for pcm are "8000" and "16000" The default value is "16000". </p>
  */
 @property (nonatomic, strong) NSString * _Nullable sampleRate;
 
@@ -825,7 +828,7 @@ typedef NS_ENUM(NSInteger, AWSPollyVoiceId) {
 @property (nonatomic, strong) NSString * _Nullable name;
 
 /**
- <p>Specifies which engines (<code>standard</code> or <code>neural</code>) that are supported by a given voice.</p>
+ <p>Specifies which engines (<code>standard</code>, <code>neural</code> or <code>long-form</code>) are supported by a given voice.</p>
  */
 @property (nonatomic, strong) NSArray<NSString *> * _Nullable supportedEngines;
 
diff --git a/AWSPolly/AWSPollyModel.m b/AWSPolly/AWSPollyModel.m
index 7916dab5281..a10cdcf95e0 100644
--- a/AWSPolly/AWSPollyModel.m
+++ b/AWSPolly/AWSPollyModel.m
@@ -63,6 +63,9 @@ + (NSValueTransformer *)engineJSONTransformer {
         if ([value caseInsensitiveCompare:@"neural"] == NSOrderedSame) {
             return @(AWSPollyEngineNeural);
         }
+        if ([value caseInsensitiveCompare:@"long-form"] == NSOrderedSame) {
+            return @(AWSPollyEngineLongForm);
+        }
         return @(AWSPollyEngineUnknown);
     } reverseBlock:^NSString *(NSNumber *value) {
         switch ([value integerValue]) {
@@ -70,6 +73,8 @@ + (NSValueTransformer *)engineJSONTransformer {
                 return @"standard";
             case AWSPollyEngineNeural:
                 return @"neural";
+            case AWSPollyEngineLongForm:
+                return @"long-form";
             default:
                 return nil;
         }
@@ -792,6 +797,9 @@ + (NSValueTransformer *)engineJSONTransformer {
         if ([value caseInsensitiveCompare:@"neural"] == NSOrderedSame) {
             return @(AWSPollyEngineNeural);
         }
+        if ([value caseInsensitiveCompare:@"long-form"] == NSOrderedSame) {
+            return @(AWSPollyEngineLongForm);
+        }
         return @(AWSPollyEngineUnknown);
     } reverseBlock:^NSString *(NSNumber *value) {
         switch ([value integerValue]) {
@@ -799,6 +807,8 @@ + (NSValueTransformer *)engineJSONTransformer {
                 return @"standard";
             case AWSPollyEngineNeural:
                 return @"neural";
+            case AWSPollyEngineLongForm:
+                return @"long-form";
             default:
                 return nil;
         }
@@ -1344,6 +1354,12 @@ + (NSValueTransformer *)voiceIdJSONTransformer {
         if ([value caseInsensitiveCompare:@"Zayd"] == NSOrderedSame) {
             return @(AWSPollyVoiceIdZayd);
         }
+        if ([value caseInsensitiveCompare:@"Danielle"] == NSOrderedSame) {
+            return @(AWSPollyVoiceIdDanielle);
+        }
+        if ([value caseInsensitiveCompare:@"Gregory"] == NSOrderedSame) {
+            return @(AWSPollyVoiceIdGregory);
+        }
         return @(AWSPollyVoiceIdUnknown);
     } reverseBlock:^NSString *(NSNumber *value) {
         switch ([value integerValue]) {
@@ -1533,6 +1549,10 @@ + (NSValueTransformer *)voiceIdJSONTransformer {
                 return @"Isabelle";
             case AWSPollyVoiceIdZayd:
                 return @"Zayd";
+            case AWSPollyVoiceIdDanielle:
+                return @"Danielle";
+            case AWSPollyVoiceIdGregory:
+                return @"Gregory";
             default:
                 return nil;
         }
@@ -1601,6 +1621,9 @@ + (NSValueTransformer *)engineJSONTransformer {
         if ([value caseInsensitiveCompare:@"neural"] == NSOrderedSame) {
             return @(AWSPollyEngineNeural);
         }
+        if ([value caseInsensitiveCompare:@"long-form"] == NSOrderedSame) {
+            return @(AWSPollyEngineLongForm);
+        }
         return @(AWSPollyEngineUnknown);
     } reverseBlock:^NSString *(NSNumber *value) {
         switch ([value integerValue]) {
@@ -1608,6 +1631,8 @@ + (NSValueTransformer *)engineJSONTransformer {
                 return @"standard";
             case AWSPollyEngineNeural:
                 return @"neural";
+            case AWSPollyEngineLongForm:
+                return @"long-form";
             default:
                 return nil;
         }
@@ -2184,6 +2209,12 @@ + (NSValueTransformer *)voiceIdJSONTransformer {
         if ([value caseInsensitiveCompare:@"Zayd"] == NSOrderedSame) {
             return @(AWSPollyVoiceIdZayd);
         }
+        if ([value caseInsensitiveCompare:@"Danielle"] == NSOrderedSame) {
+            return @(AWSPollyVoiceIdDanielle);
+        }
+        if ([value caseInsensitiveCompare:@"Gregory"] == NSOrderedSame) {
+            return @(AWSPollyVoiceIdGregory);
+        }
         return @(AWSPollyVoiceIdUnknown);
     } reverseBlock:^NSString *(NSNumber *value) {
         switch ([value integerValue]) {
@@ -2373,6 +2404,10 @@ + (NSValueTransformer *)voiceIdJSONTransformer {
                 return @"Isabelle";
             case AWSPollyVoiceIdZayd:
                 return @"Zayd";
+            case AWSPollyVoiceIdDanielle:
+                return @"Danielle";
+            case AWSPollyVoiceIdGregory:
+                return @"Gregory";
             default:
                 return nil;
         }
@@ -2409,6 +2444,9 @@ + (NSValueTransformer *)engineJSONTransformer {
         if ([value caseInsensitiveCompare:@"neural"] == NSOrderedSame) {
             return @(AWSPollyEngineNeural);
         }
+        if ([value caseInsensitiveCompare:@"long-form"] == NSOrderedSame) {
+            return @(AWSPollyEngineLongForm);
+        }
         return @(AWSPollyEngineUnknown);
     } reverseBlock:^NSString *(NSNumber *value) {
         switch ([value integerValue]) {
@@ -2416,6 +2454,8 @@ + (NSValueTransformer *)engineJSONTransformer {
                 return @"standard";
             case AWSPollyEngineNeural:
                 return @"neural";
+            case AWSPollyEngineLongForm:
+                return @"long-form";
             default:
                 return nil;
         }
@@ -2961,6 +3001,12 @@ + (NSValueTransformer *)voiceIdJSONTransformer {
         if ([value caseInsensitiveCompare:@"Zayd"] == NSOrderedSame) {
             return @(AWSPollyVoiceIdZayd);
         }
+        if ([value caseInsensitiveCompare:@"Danielle"] == NSOrderedSame) {
+            return @(AWSPollyVoiceIdDanielle);
+        }
+        if ([value caseInsensitiveCompare:@"Gregory"] == NSOrderedSame) {
+            return @(AWSPollyVoiceIdGregory);
+        }
         return @(AWSPollyVoiceIdUnknown);
     } reverseBlock:^NSString *(NSNumber *value) {
         switch ([value integerValue]) {
@@ -3150,6 +3196,10 @@ + (NSValueTransformer *)voiceIdJSONTransformer {
                 return @"Isabelle";
             case AWSPollyVoiceIdZayd:
                 return @"Zayd";
+            case AWSPollyVoiceIdDanielle:
+                return @"Danielle";
+            case AWSPollyVoiceIdGregory:
+                return @"Gregory";
             default:
                 return nil;
         }
@@ -3494,6 +3544,12 @@ + (NSValueTransformer *)identifierJSONTransformer {
         if ([value caseInsensitiveCompare:@"Zayd"] == NSOrderedSame) {
             return @(AWSPollyVoiceIdZayd);
         }
+        if ([value caseInsensitiveCompare:@"Danielle"] == NSOrderedSame) {
+            return @(AWSPollyVoiceIdDanielle);
+        }
+        if ([value caseInsensitiveCompare:@"Gregory"] == NSOrderedSame) {
+            return @(AWSPollyVoiceIdGregory);
+        }
         return @(AWSPollyVoiceIdUnknown);
     } reverseBlock:^NSString *(NSNumber *value) {
         switch ([value integerValue]) {
@@ -3683,6 +3739,10 @@ + (NSValueTransformer *)identifierJSONTransformer {
                 return @"Isabelle";
             case AWSPollyVoiceIdZayd:
                 return @"Zayd";
+            case AWSPollyVoiceIdDanielle:
+                return @"Danielle";
+            case AWSPollyVoiceIdGregory:
+                return @"Gregory";
             default:
                 return nil;
         }
diff --git a/AWSPolly/AWSPollyResources.m b/AWSPolly/AWSPollyResources.m
index 4bae4f49df3..f69e216430c 100644
--- a/AWSPolly/AWSPollyResources.m
+++ b/AWSPolly/AWSPollyResources.m
@@ -257,7 +257,7 @@ - (NSString *)definitionString {
       \"members\":{\
         \"Engine\":{\
           \"shape\":\"Engine\",\
-          \"documentation\":\"<p>Specifies the engine (<code>standard</code> or <code>neural</code>) used by Amazon Polly when processing input text for speech synthesis. </p>\",\
+          \"documentation\":\"<p>Specifies the engine (<code>standard</code>, <code>neural</code> or <code>long-form</code>) used by Amazon Polly when processing input text for speech synthesis. </p>\",\
           \"location\":\"querystring\",\
           \"locationName\":\"Engine\"\
         },\
@@ -298,7 +298,8 @@ - (NSString *)definitionString {
       \"type\":\"string\",\
       \"enum\":[\
         \"standard\",\
-        \"neural\"\
+        \"neural\",\
+        \"long-form\"\
       ]\
     },\
     \"EngineList\":{\
@@ -785,7 +786,7 @@ - (NSString *)definitionString {
       \"members\":{\
         \"Engine\":{\
           \"shape\":\"Engine\",\
-          \"documentation\":\"<p>Specifies the engine (<code>standard</code> or <code>neural</code>) for Amazon Polly to use when processing input text for speech synthesis. Using a voice that is not supported for the engine selected will result in an error.</p>\"\
+          \"documentation\":\"<p>Specifies the engine (<code>standard</code>, <code>neural</code> or <code>long-form</code>) for Amazon Polly to use when processing input text for speech synthesis. Using a voice that is not supported for the engine selected will result in an error.</p>\"\
         },\
         \"LanguageCode\":{\
           \"shape\":\"LanguageCode\",\
@@ -809,7 +810,7 @@ - (NSString *)definitionString {
         },\
         \"SampleRate\":{\
           \"shape\":\"SampleRate\",\
-          \"documentation\":\"<p>The audio frequency specified in Hz.</p> <p>The valid values for mp3 and ogg_vorbis are \\\"8000\\\", \\\"16000\\\", \\\"22050\\\", and \\\"24000\\\". The default value for standard voices is \\\"22050\\\". The default value for neural voices is \\\"24000\\\".</p> <p>Valid values for pcm are \\\"8000\\\" and \\\"16000\\\" The default value is \\\"16000\\\". </p>\"\
+          \"documentation\":\"<p>The audio frequency specified in Hz.</p> <p>The valid values for mp3 and ogg_vorbis are \\\"8000\\\", \\\"16000\\\", \\\"22050\\\", and \\\"24000\\\". The default value for standard voices is \\\"22050\\\". The default value for neural voices is \\\"24000\\\". The default value for long-form voices is \\\"24000\\\".</p> <p>Valid values for pcm are \\\"8000\\\" and \\\"16000\\\" The default value is \\\"16000\\\". </p>\"\
         },\
         \"SnsTopicArn\":{\
           \"shape\":\"SnsTopicArn\",\
@@ -847,7 +848,7 @@ - (NSString *)definitionString {
       \"members\":{\
         \"Engine\":{\
           \"shape\":\"Engine\",\
-          \"documentation\":\"<p>Specifies the engine (<code>standard</code> or <code>neural</code>) for Amazon Polly to use when processing input text for speech synthesis. Using a voice that is not supported for the engine selected will result in an error.</p>\"\
+          \"documentation\":\"<p>Specifies the engine (<code>standard</code>, <code>neural</code> or <code>long-form</code>) for Amazon Polly to use when processing input text for speech synthesis. Using a voice that is not supported for the engine selected will result in an error.</p>\"\
         },\
         \"TaskId\":{\
           \"shape\":\"TaskId\",\
@@ -887,7 +888,7 @@ - (NSString *)definitionString {
         },\
         \"SampleRate\":{\
           \"shape\":\"SampleRate\",\
-          \"documentation\":\"<p>The audio frequency specified in Hz.</p> <p>The valid values for mp3 and ogg_vorbis are \\\"8000\\\", \\\"16000\\\", \\\"22050\\\", and \\\"24000\\\". The default value for standard voices is \\\"22050\\\". The default value for neural voices is \\\"24000\\\".</p> <p>Valid values for pcm are \\\"8000\\\" and \\\"16000\\\" The default value is \\\"16000\\\". </p>\"\
+          \"documentation\":\"<p>The audio frequency specified in Hz.</p> <p>The valid values for mp3 and ogg_vorbis are \\\"8000\\\", \\\"16000\\\", \\\"22050\\\", and \\\"24000\\\". The default value for standard voices is \\\"22050\\\". The default value for neural voices is \\\"24000\\\". The default value for long-form voices is \\\"24000\\\".</p> <p>Valid values for pcm are \\\"8000\\\" and \\\"16000\\\" The default value is \\\"16000\\\". </p>\"\
         },\
         \"SpeechMarkTypes\":{\
           \"shape\":\"SpeechMarkTypeList\",\
@@ -931,7 +932,7 @@ - (NSString *)definitionString {
       \"members\":{\
         \"Engine\":{\
           \"shape\":\"Engine\",\
-          \"documentation\":\"<p>Specifies the engine (<code>standard</code> or <code>neural</code>) for Amazon Polly to use when processing input text for speech synthesis. For information on Amazon Polly voices and which voices are available in standard-only, NTTS-only, and both standard and NTTS formats, see <a href=\\\"https://docs.aws.amazon.com/polly/latest/dg/voicelist.html\\\">Available Voices</a>.</p> <p> <b>NTTS-only voices</b> </p> <p>When using NTTS-only voices such as Kevin (en-US), this parameter is required and must be set to <code>neural</code>. If the engine is not specified, or is set to <code>standard</code>, this will result in an error. </p> <p>Type: String</p> <p>Valid Values: <code>standard</code> | <code>neural</code> </p> <p>Required: Yes</p> <p> <b>Standard voices</b> </p> <p>For standard voices, this is not required; the engine parameter defaults to <code>standard</code>. If the engine is not specified, or is set to <code>standard</code> and an NTTS-only voice is selected, this will result in an error. </p>\"\
+          \"documentation\":\"<p>Specifies the engine (<code>standard</code>, <code>neural</code> or <code>long-form</code>) for Amazon Polly to use when processing input text for speech synthesis. For information on Amazon Polly voices and which voices are available for each engine, see <a href=\\\"https://docs.aws.amazon.com/polly/latest/dg/voicelist.html\\\">Available Voices</a>.</p> <p> <b>NTTS-only voices</b> </p> <p>When using NTTS-only voices such as Kevin (en-US), this parameter is required and must be set to <code>neural</code>. If the engine is not specified, or is set to <code>standard</code>, this will result in an error. </p> <p> <b>long-form-only voices</b> </p> <p>When using long-form-only voices such as Danielle (en-US), this parameter is required and must be set to <code>long-form</code>. If the engine is not specified, or is set to <code>standard</code> or <code>neural</code>, this will result in an error. </p> <p>Type: String</p> <p>Valid Values: <code>standard</code> | <code>neural</code> | <code>long-form</code> </p> <p>Required: Yes</p> <p> <b>Standard voices</b> </p> <p>For standard voices, this is not required; the engine parameter defaults to <code>standard</code>. If the engine is not specified, or is set to <code>standard</code> and an NTTS-only voice is selected, this will result in an error. </p>\"\
         },\
         \"LanguageCode\":{\
           \"shape\":\"LanguageCode\",\
@@ -947,7 +948,7 @@ - (NSString *)definitionString {
         },\
         \"SampleRate\":{\
           \"shape\":\"SampleRate\",\
-          \"documentation\":\"<p>The audio frequency specified in Hz.</p> <p>The valid values for mp3 and ogg_vorbis are \\\"8000\\\", \\\"16000\\\", \\\"22050\\\", and \\\"24000\\\". The default value for standard voices is \\\"22050\\\". The default value for neural voices is \\\"24000\\\".</p> <p>Valid values for pcm are \\\"8000\\\" and \\\"16000\\\" The default value is \\\"16000\\\". </p>\"\
+          \"documentation\":\"<p>The audio frequency specified in Hz.</p> <p>The valid values for mp3 and ogg_vorbis are \\\"8000\\\", \\\"16000\\\", \\\"22050\\\", and \\\"24000\\\". The default value for standard voices is \\\"22050\\\". The default value for neural voices is \\\"24000\\\". The default value for long-form voices is \\\"24000\\\".</p> <p>Valid values for pcm are \\\"8000\\\" and \\\"16000\\\" The default value is \\\"16000\\\". </p>\"\
         },\
         \"SpeechMarkTypes\":{\
           \"shape\":\"SpeechMarkTypeList\",\
@@ -1067,7 +1068,7 @@ - (NSString *)definitionString {
         },\
         \"SupportedEngines\":{\
           \"shape\":\"EngineList\",\
-          \"documentation\":\"<p>Specifies which engines (<code>standard</code> or <code>neural</code>) that are supported by a given voice.</p>\"\
+          \"documentation\":\"<p>Specifies which engines (<code>standard</code>, <code>neural</code> or <code>long-form</code>) are supported by a given voice.</p>\"\
         }\
       },\
       \"documentation\":\"<p>Description of the voice.</p>\"\
@@ -1167,7 +1168,9 @@ - (NSString *)definitionString {
         \"Sofie\",\
         \"Lisa\",\
         \"Isabelle\",\
-        \"Zayd\"\
+        \"Zayd\",\
+        \"Danielle\",\
+        \"Gregory\"\
       ]\
     },\
     \"VoiceList\":{\