diff --git a/CHANGELOG.md b/CHANGELOG.md
index d1cd790..d0133f8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,10 @@
 
 ## NOT RELEASED
 
+### Added
+
+- AWS api-change: Supporting GitLab and GitLab Self Managed as source types in AWS CodeBuild.
+
 ### Changed
 
 - AWS enhancement: Documentation updates.
diff --git a/composer.json b/composer.json
index b6204bb..3a983c8 100644
--- a/composer.json
+++ b/composer.json
@@ -28,7 +28,7 @@
     },
     "extra": {
         "branch-alias": {
-            "dev-master": "2.3-dev"
+            "dev-master": "2.4-dev"
         }
     }
 }
diff --git a/src/Enum/SourceAuthType.php b/src/Enum/SourceAuthType.php
index f0d9e84..85dda36 100644
--- a/src/Enum/SourceAuthType.php
+++ b/src/Enum/SourceAuthType.php
@@ -4,11 +4,13 @@
 
 final class SourceAuthType
 {
+    public const CODECONNECTIONS = 'CODECONNECTIONS';
     public const OAUTH = 'OAUTH';
 
     public static function exists(string $value): bool
     {
         return isset([
+            self::CODECONNECTIONS => true,
             self::OAUTH => true,
         ][$value]);
     }
diff --git a/src/Enum/SourceType.php b/src/Enum/SourceType.php
index 178c64f..be95e08 100644
--- a/src/Enum/SourceType.php
+++ b/src/Enum/SourceType.php
@@ -9,6 +9,8 @@ final class SourceType
     public const CODEPIPELINE = 'CODEPIPELINE';
     public const GITHUB = 'GITHUB';
     public const GITHUB_ENTERPRISE = 'GITHUB_ENTERPRISE';
+    public const GITLAB = 'GITLAB';
+    public const GITLAB_SELF_MANAGED = 'GITLAB_SELF_MANAGED';
     public const NO_SOURCE = 'NO_SOURCE';
     public const S3 = 'S3';
 
@@ -20,6 +22,8 @@ public static function exists(string $value): bool
             self::CODEPIPELINE => true,
             self::GITHUB => true,
             self::GITHUB_ENTERPRISE => true,
+            self::GITLAB => true,
+            self::GITLAB_SELF_MANAGED => true,
             self::NO_SOURCE => true,
             self::S3 => true,
         ][$value]);
diff --git a/src/ValueObject/ProjectSource.php b/src/ValueObject/ProjectSource.php
index 3cef64e..99b3ef3 100644
--- a/src/ValueObject/ProjectSource.php
+++ b/src/ValueObject/ProjectSource.php
@@ -16,8 +16,10 @@ final class ProjectSource
      * - `BITBUCKET`: The source code is in a Bitbucket repository.
      * - `CODECOMMIT`: The source code is in an CodeCommit repository.
      * - `CODEPIPELINE`: The source code settings are specified in the source action of a pipeline in CodePipeline.
-     * - `GITHUB`: The source code is in a GitHub or GitHub Enterprise Cloud repository.
+     * - `GITHUB`: The source code is in a GitHub repository.
      * - `GITHUB_ENTERPRISE`: The source code is in a GitHub Enterprise Server repository.
+     * - `GITLAB`: The source code is in a GitLab repository.
+     * - `GITLAB_SELF_MANAGED`: The source code is in a self-managed GitLab repository.
      * - `NO_SOURCE`: The project does not have input source code.
      * - `S3`: The source code is in an Amazon S3 bucket.
      *
@@ -48,6 +50,14 @@ final class ProjectSource
      *   want to allow CodeBuild to have access to, and then choose **Authorize application**. (After you have connected to
      *   your GitHub account, you do not need to finish creating the build project. You can leave the CodeBuild console.) To
      *   instruct CodeBuild to use this connection, in the `source` object, set the `auth` object's `type` value to `OAUTH`.
+     * - For source code in an GitLab or self-managed GitLab repository, the HTTPS clone URL to the repository that contains
+     *   the source and the buildspec file. You must connect your Amazon Web Services account to your GitLab account. Use
+     *   the CodeBuild console to start creating a build project. When you use the console to connect (or reconnect) with
+     *   GitLab, on the Connections **Authorize application** page, choose **Authorize**. Then on the CodeStar Connections
+     *   **Create GitLab connection** page, choose **Connect to GitLab**. (After you have connected to your GitLab account,
+     *   you do not need to finish creating the build project. You can leave the CodeBuild console.) To instruct CodeBuild
+     *   to override the default connection and use this connection instead, set the `auth` object's `type` value to
+     *   `CODECONNECTIONS` in the `source` object.
      * - For source code in a Bitbucket repository, the HTTPS clone URL to the repository that contains the source and the
      *   buildspec file. You must connect your Amazon Web Services account to your Bitbucket account. Use the CodeBuild
      *   console to start creating a build project. When you use the console to connect (or reconnect) with Bitbucket, on
@@ -103,8 +113,8 @@ final class ProjectSource
 
     /**
      * Set to true to report the status of a build's start and finish to your source provider. This option is valid only
-     * when your source provider is GitHub, GitHub Enterprise, or Bitbucket. If this is set and you use a different source
-     * provider, an `invalidInputException` is thrown.
+     * when your source provider is GitHub, GitHub Enterprise, GitLab, GitLab Self Managed, or Bitbucket. If this is set and
+     * you use a different source provider, an `invalidInputException` is thrown.
      *
      * To be able to report the build status to the source provider, the user associated with the source provider must have
      * write access to the repo. If the user does not have write access, the build status cannot be updated. For more
diff --git a/src/ValueObject/ProjectSourceVersion.php b/src/ValueObject/ProjectSourceVersion.php
index 748b211..62ffe83 100644
--- a/src/ValueObject/ProjectSourceVersion.php
+++ b/src/ValueObject/ProjectSourceVersion.php
@@ -21,9 +21,9 @@ final class ProjectSourceVersion
      * The source version for the corresponding source identifier. If specified, must be one of:
      *
      * - For CodeCommit: the commit ID, branch, or Git tag to use.
-     * - For GitHub: the commit ID, pull request ID, branch name, or tag name that corresponds to the version of the source
-     *   code you want to build. If a pull request ID is specified, it must use the format `pr/pull-request-ID` (for
-     *   example, `pr/25`). If a branch name is specified, the branch's HEAD commit ID is used. If not specified, the
+     * - For GitHub or GitLab: the commit ID, pull request ID, branch name, or tag name that corresponds to the version of
+     *   the source code you want to build. If a pull request ID is specified, it must use the format `pr/pull-request-ID`
+     *   (for example, `pr/25`). If a branch name is specified, the branch's HEAD commit ID is used. If not specified, the
      *   default branch's HEAD commit ID is used.
      * - For Bitbucket: the commit ID, branch name, or tag name that corresponds to the version of the source code you want
      *   to build. If a branch name is specified, the branch's HEAD commit ID is used. If not specified, the default
diff --git a/src/ValueObject/SourceAuth.php b/src/ValueObject/SourceAuth.php
index 0eb48a3..b60036f 100644
--- a/src/ValueObject/SourceAuth.php
+++ b/src/ValueObject/SourceAuth.php
@@ -13,9 +13,7 @@
 final class SourceAuth
 {
     /**
-     * > This data type is deprecated and is no longer accurate or used.
-     *
-     * The authorization type to use. The only valid value is `OAUTH`, which represents the OAuth authorization type.
+     * The authorization type to use. Valid options are OAUTH or CODECONNECTIONS.
      *
      * @var SourceAuthType::*
      */