diff --git a/Changelog.md b/Changelog.md
index fdccb5dc..8bca3c3b 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -7,6 +7,7 @@ https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG.md) for the list o
 - gitlab: upgrade CE to v10.5.0
 - Add `GITLAB_UPLOADS_STORAGE_PATH`
 - Add `GITLAB_UPLOADS_BASE_DIR`
+- Add `LDAP_LOWERCASE_USERNAMES`
 
 **10.4.4**
 - gitlab: upgrade CE to v10.4.4
diff --git a/README.md b/README.md
index afe9d2a1..1f575b64 100644
--- a/README.md
+++ b/README.md
@@ -961,6 +961,7 @@ Below is the complete list of available options that can be used to customize yo
 | `LDAP_BLOCK_AUTO_CREATED_USERS` | Locks down those users until they have been cleared by the admin. Defaults to `false`. |
 | `LDAP_BASE` | Base where we can search for users. No default. |
 | `LDAP_USER_FILTER` | Filter LDAP users. No default. |
+| `LDAP_LOWERCASE_USERNAMES` | GitLab will lower case the username for the LDAP Server. Defaults to `false` |
 | `OAUTH_ENABLED` | Enable OAuth support. Defaults to `true` if any of the support OAuth providers is configured, else defaults to `false`. |
 | `OAUTH_AUTO_SIGN_IN_WITH_PROVIDER` | Automatically sign in with a specific OAuth provider without showing GitLab sign-in page. Accepted values are `cas3`, `github`, `bitbucket`, `gitlab`, `google_oauth2`, `facebook`, `twitter`, `saml`, `crowd`, `auth0` and `azure_oauth2`. No default. |
 | `OAUTH_ALLOW_SSO` | Comma separated list of oauth providers for single sign-on. This allows users to login without having a user account. The account is created automatically when authentication is successful. Accepted values are `cas3`, `github`, `bitbucket`, `gitlab`, `google_oauth2`, `facebook`, `twitter`, `saml`, `crowd`, `auth0` and `azure_oauth2`. No default. |
diff --git a/assets/runtime/config/gitlabhq/gitlab.yml b/assets/runtime/config/gitlabhq/gitlab.yml
index 51fb1a4d..c35baf3f 100644
--- a/assets/runtime/config/gitlabhq/gitlab.yml
+++ b/assets/runtime/config/gitlabhq/gitlab.yml
@@ -342,6 +342,9 @@ production: &base
           first_name: 'givenName'
           last_name:  'sn'
 
+          # If lowercase_usernames is enabled, GitLab will lower case the username.
+          lowercase_usernames: {{LDAP_LOWERCASE_USERNAMES}}
+
       # GitLab EE only: add more LDAP servers
       # Choose an ID made of a-z and 0-9 . This ID will be stored in the database
       # so that GitLab can remember which LDAP server a user belongs to.
diff --git a/assets/runtime/env-defaults b/assets/runtime/env-defaults
index 57c20bd8..6d9f7003 100644
--- a/assets/runtime/env-defaults
+++ b/assets/runtime/env-defaults
@@ -242,6 +242,7 @@ LDAP_ACTIVE_DIRECTORY=${LDAP_ACTIVE_DIRECTORY:-true}
 LDAP_BLOCK_AUTO_CREATED_USERS=${LDAP_BLOCK_AUTO_CREATED_USERS:-false}
 LDAP_BASE=${LDAP_BASE:-}
 LDAP_USER_FILTER=${LDAP_USER_FILTER:-}
+LDAP_LOWERCASE_USERNAMES="${LDAP_LOWERCASE_USERNAMES:-false}"
 LDAP_LABEL=${LDAP_LABEL:-LDAP}
 LDAP_ALLOW_USERNAME_OR_EMAIL_LOGIN=${LDAP_ALLOW_USERNAME_OR_EMAIL_LOGIN:-}
 case ${LDAP_UID} in
diff --git a/assets/runtime/functions b/assets/runtime/functions
index 2241ca97..6c6a1f2b 100644
--- a/assets/runtime/functions
+++ b/assets/runtime/functions
@@ -455,6 +455,7 @@ gitlab_configure_ldap() {
     LDAP_BLOCK_AUTO_CREATED_USERS \
     LDAP_BASE \
     LDAP_USER_FILTER \
+    LDAP_LOWERCASE_USERNAMES \
     LDAP_LABEL
 }