diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5da9c54b89..bb4cab98ba 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,10 @@ CHANGELOG
 3.16.0
 ------
 
+**CHANGES**
+- The validator `ClusterNameValidator` now enforces cluster names to be limited to 40 characters when using `ExternalSlurmdbd`, 
+  consistent with the existing limit for `Database`. This prevents runtime failures caused by MySQL's table name length limit.
+
 **BUG FIXES**
 - Fix sporadic S3 bucket (with name parallelcluster-*-v1-do-not-delete) creation failure when multiple create-cluster commands are running simultaneously in the same region.
 
diff --git a/cli/src/pcluster/validators/cluster_validators.py b/cli/src/pcluster/validators/cluster_validators.py
index c99a430627..58c863b729 100644
--- a/cli/src/pcluster/validators/cluster_validators.py
+++ b/cli/src/pcluster/validators/cluster_validators.py
@@ -89,7 +89,9 @@ class ClusterNameValidator(Validator):
     """Cluster name validator."""
 
     def _validate(self, name, scheduling):
-        if scheduling.scheduler == "slurm" and scheduling.settings.database is not None:
+        if scheduling.scheduler == "slurm" and (
+            scheduling.settings.database is not None or scheduling.settings.external_slurmdbd is not None
+        ):
             if not re.match(PCLUSTER_NAME_REGEX % (PCLUSTER_NAME_MAX_LENGTH_SLURM_ACCOUNTING - 1), name):
                 self._add_failure(
                     (
diff --git a/cli/tests/pcluster/validators/test_cluster_validators.py b/cli/tests/pcluster/validators/test_cluster_validators.py
index c1ec976ccb..68c1cd48ef 100644
--- a/cli/tests/pcluster/validators/test_cluster_validators.py
+++ b/cli/tests/pcluster/validators/test_cluster_validators.py
@@ -192,6 +192,26 @@ def test_cluster_name_validator(cluster_name, scheduling, should_trigger_error):
             ),
             False,
         ),
+        (
+            "ClusterNameWith40------------------Chars",
+            SlurmScheduling(
+                queues=None,
+                settings=SlurmSettings(
+                    external_slurmdbd=ExternalSlurmdbd(host="test.slurmdbd.host", port=6819),
+                ),
+            ),
+            False,
+        ),
+        (
+            "ClusterNameWith41-------------------Chars",
+            SlurmScheduling(
+                queues=None,
+                settings=SlurmSettings(
+                    external_slurmdbd=ExternalSlurmdbd(host="test.slurmdbd.host", port=6819),
+                ),
+            ),
+            True,
+        ),
     ],
 )
 def test_cluster_name_validator_slurm_accounting(cluster_name, scheduling, should_trigger_error):