diff --git a/manifest.json b/manifest.json
index 8c442f351..a70b50556 100644
--- a/manifest.json
+++ b/manifest.json
@@ -1,6 +1,6 @@
 {
     "variables": {
-        "${LATEST}": "3.340.1"
+        "${LATEST}": "3.340.4"
     },
     "endpoints": "https://raw.githubusercontent.com/aws/aws-sdk-php/${LATEST}/src/data/endpoints.json",
     "services": {
diff --git a/src/Service/Ssm/src/Exception/ParameterNotFoundException.php b/src/Service/Ssm/src/Exception/ParameterNotFoundException.php
index b69c20230..b9ee12891 100644
--- a/src/Service/Ssm/src/Exception/ParameterNotFoundException.php
+++ b/src/Service/Ssm/src/Exception/ParameterNotFoundException.php
@@ -6,6 +6,9 @@
 
 /**
  * The parameter couldn't be found. Verify the name and try again.
+ *
+ * > For the `DeleteParameter` and `GetParameter` actions, if the specified parameter doesn't exist, the
+ * > `ParameterNotFound` exception is *not* recorded in CloudTrail event logs.
  */
 final class ParameterNotFoundException extends ClientException
 {
diff --git a/src/Service/Ssm/src/Input/PutParameterRequest.php b/src/Service/Ssm/src/Input/PutParameterRequest.php
index 99739ad31..b2fec2410 100644
--- a/src/Service/Ssm/src/Input/PutParameterRequest.php
+++ b/src/Service/Ssm/src/Input/PutParameterRequest.php
@@ -13,7 +13,7 @@
 final class PutParameterRequest extends Input
 {
     /**
-     * The fully qualified name of the parameter that you want to add to the system.
+     * The fully qualified name of the parameter that you want to create or update.
      *
      * > You can't enter the Amazon Resource Name (ARN) for a parameter, only the parameter name itself.
      *
@@ -71,7 +71,7 @@ final class PutParameterRequest extends Input
     private $value;
 
     /**
-     * The type of parameter that you want to add to the system.
+     * The type of parameter that you want to create.
      *
      * > `SecureString` isn't currently supported for CloudFormation templates.
      *
@@ -89,8 +89,8 @@ final class PutParameterRequest extends Input
      * The Key Management Service (KMS) ID that you want to use to encrypt a parameter. Use a custom key for better
      * security. Required for parameters that use the `SecureString` data type.
      *
-     * If you don't specify a key ID, the system uses the default key associated with your Amazon Web Services account which
-     * is not as secure as using a custom key.
+     * If you don't specify a key ID, the system uses the default key associated with your Amazon Web Services account,
+     * which is not as secure as using a custom key.
      *
      * - To use a custom KMS key, choose the `SecureString` data type with the `Key ID` parameter.
      *
diff --git a/src/Service/Ssm/src/SsmClient.php b/src/Service/Ssm/src/SsmClient.php
index 3de5c95ca..e4d0af197 100644
--- a/src/Service/Ssm/src/SsmClient.php
+++ b/src/Service/Ssm/src/SsmClient.php
@@ -203,7 +203,7 @@ public function getParametersByPath($input): GetParametersByPathResult
     }
 
     /**
-     * Add a parameter to the system.
+     * Create or update a parameter in Parameter Store.
      *
      * @see https://docs.aws.amazon.com/systems-manager/latest/APIReference/API_PutParameter.html
      * @see https://docs.aws.amazon.com/aws-sdk-php/v3/api/api-ssm-2014-11-06.html#putparameter