diff --git a/.github/workflows/checks.yml b/.github/workflows/checks.yml
index 75561f370f5e..cde8cfb205d3 100755
--- a/.github/workflows/checks.yml
+++ b/.github/workflows/checks.yml
@@ -23,7 +23,7 @@ jobs:
         uses: shivammathur/setup-php@v2
         with:
           php-version: ${{ matrix.php }}
-          extensions: dom, curl, libxml, mbstring, zip, gd, json, readline, xsl, imagick
+          extensions: dom, curl, libxml, mbstring, zip, gd, json, readline, xsl, imagick, gettext
           tools: composer:v2
           coverage: none
 
diff --git a/.github/workflows/code-rules.yml b/.github/workflows/code-rules.yml
index b7730c2bf5e2..39c2dc05b99d 100644
--- a/.github/workflows/code-rules.yml
+++ b/.github/workflows/code-rules.yml
@@ -16,7 +16,7 @@ jobs:
         uses: shivammathur/setup-php@v2
         with:
           php-version: '8.4'
-          extensions: dom, curl, libxml, mbstring, zip, gd, json, readline, xsl, imagick
+          extensions: dom, curl, libxml, mbstring, zip, gd, json, readline, xsl, imagick, gettext
           tools: composer:v2
           coverage: none
 
diff --git a/.github/workflows/install-check-trunk-8.4.yml b/.github/workflows/install-check-trunk-8.4.yml
index 97dde5cff33b..77f8e1872a5e 100644
--- a/.github/workflows/install-check-trunk-8.4.yml
+++ b/.github/workflows/install-check-trunk-8.4.yml
@@ -34,7 +34,7 @@ jobs:
         uses: shivammathur/setup-php@v2
         with:
           php-version: ${{ matrix.php }}
-          extensions: dom, curl, libxml, mbstring, zip, gd, json, readline, xsl, xml, mysql
+          extensions: dom, curl, libxml, mbstring, zip, gd, json, readline, xsl, xml, mysql, gettext
           tools: composer:v2
           coverage: none
 
diff --git a/.github/workflows/install-check-trunk-8.5.yml b/.github/workflows/install-check-trunk-8.5.yml
index 2d4770e4a0d5..5db6c0afdc4f 100644
--- a/.github/workflows/install-check-trunk-8.5.yml
+++ b/.github/workflows/install-check-trunk-8.5.yml
@@ -34,7 +34,7 @@ jobs:
         uses: shivammathur/setup-php@v2
         with:
           php-version: ${{ matrix.php }}
-          extensions: dom, curl, libxml, mbstring, zip, gd, json, readline, xsl, xml, mysql
+          extensions: dom, curl, libxml, mbstring, zip, gd, json, readline, xsl, xml, mysql, gettext
           tools: composer:v2
           coverage: none
 
diff --git a/.github/workflows/legacy-ui.yml b/.github/workflows/legacy-ui.yml
index d3aa8b1acfce..491aea3a9d3b 100755
--- a/.github/workflows/legacy-ui.yml
+++ b/.github/workflows/legacy-ui.yml
@@ -35,7 +35,7 @@ jobs:
         uses: shivammathur/setup-php@v2
         with:
           php-version: 8.4
-          extensions: dom, curl, libxml, mbstring, zip, gd, json, readline, xsl, xml, mysql
+          extensions: dom, curl, libxml, mbstring, zip, gd, json, readline, xsl, xml, mysql, gettext
           tools: composer:v2
           coverage: none
 
diff --git a/composer.json b/composer.json
index 5197e1b5ec6f..e999216eb571 100755
--- a/composer.json
+++ b/composer.json
@@ -50,6 +50,7 @@
 		"ext-xml": "*",
 		"ext-zip": "*",
 		"ext-imagick": "*",
+		"ext-gettext": "*",
 		"bacon/bacon-qr-code": "^3.0",
 		"celtic/lti": "^5.4.7",
 		"dflydev/fig-cookies": "^3.1.0",
diff --git a/composer.lock b/composer.lock
index 0e3d6f57af31..073940172e60 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "2b858b71ec8bdfbcbf1a4de417423914",
+    "content-hash": "91192277b93b05693d4426e61cf0a70e",
     "packages": [
         {
             "name": "bacon/bacon-qr-code",
@@ -11128,7 +11128,8 @@
         "ext-libxml": "*",
         "ext-xml": "*",
         "ext-zip": "*",
-        "ext-imagick": "*"
+        "ext-imagick": "*",
+        "ext-gettext": "*"
     },
     "platform-dev": {},
     "plugin-api-version": "2.9.0"
diff --git a/docs/configuration/install.md b/docs/configuration/install.md
index 543ed55dba6c..200a49ff11e4 100755
--- a/docs/configuration/install.md
+++ b/docs/configuration/install.md
@@ -113,9 +113,13 @@ Other web servers capable of processing PHP, such as Nginx or Apache2 with FCGI
 
 **Required PHP Extensions:**
 ```
-gd, dom, xsl, pdo, pdo_mysql, curl, json, simplexml, libxml, xml, zip, imagick, mbstring
+gd, dom, xsl, pdo, pdo_mysql, curl, json, simplexml, libxml, xml, zip, imagick, mbstring, gettext
 ```
 
+ILIAS serves its translations through native gettext: the PHP extension `gettext` and the C library's
+`C.utf8` locale (glibc) MUST be available to the PHP of the web server as well as to the CLI. Without them
+the user interface shows identifiers (e.g. `-login-`) instead of texts.
+
 **Optional PHP Extensions:**
 
 * `soap` for SOAP user administration