diff --git a/releng/download/releases/11.3/README.txt b/releng/download/releases/11.3/README.txt
new file mode 100644
index 00000000000..71ab63ef5d2
--- /dev/null
+++ b/releng/download/releases/11.3/README.txt
@@ -0,0 +1,3 @@
+This is the release directory for CDT 11.3.
+
+The CDT 11.3.1 subdirectory is not included in the composites, see https://github.com/eclipse-cdt/cdt/issues/551 for details.
diff --git a/releng/download/releases/11.3/compositeArtifacts.xml b/releng/download/releases/11.3/compositeArtifacts.xml
index 5798128b787..8f4483a9e5a 100644
--- a/releng/download/releases/11.3/compositeArtifacts.xml
+++ b/releng/download/releases/11.3/compositeArtifacts.xml
@@ -8,5 +8,6 @@
   </properties>
   <children size='1'>
     <child location='cdt-11.3.0'/>
+    <!-- CDT 11.3.1 is not included as it exists only for releng reasons, see details in https://github.com/eclipse-cdt/cdt/issues/551 -->
   </children>
 </repository>
diff --git a/releng/download/releases/11.3/compositeContent.xml b/releng/download/releases/11.3/compositeContent.xml
index 5af4126de7f..c53d6189c90 100644
--- a/releng/download/releases/11.3/compositeContent.xml
+++ b/releng/download/releases/11.3/compositeContent.xml
@@ -8,5 +8,6 @@
   </properties>
   <children size='1'>
     <child location='cdt-11.3.0'/>
+    <!-- CDT 11.3.1 is not included as it exists only for releng reasons, see details in https://github.com/eclipse-cdt/cdt/issues/551 -->
   </children>
 </repository>