diff --git a/elasticsearch/src/main/java/org/elasticsearch/xpack/prelert/job/Job.java b/elasticsearch/src/main/java/org/elasticsearch/xpack/prelert/job/Job.java
index cd8392616f1..2b12806fd7b 100644
--- a/elasticsearch/src/main/java/org/elasticsearch/xpack/prelert/job/Job.java
+++ b/elasticsearch/src/main/java/org/elasticsearch/xpack/prelert/job/Job.java
@@ -718,7 +718,7 @@ public class Job extends AbstractDiffable<Job> implements Writeable, ToXContent
                     id = this.id;
                 } else {
                     // Base64 UUIDs are not necessarily valid job IDs
-                    id = "auto-" + UUIDs.base64UUID().toLowerCase(Locale.ROOT).replaceAll("/\\+=", "_");
+                    id = "auto-" + UUIDs.base64UUID().toLowerCase(Locale.ROOT).replaceAll("[/+=-]", "_");
                     if (id.endsWith("_")) {
                         // Job IDs cannot end with underscores
                         id = id.substring(0, id.length() - 1) + "z";
@@ -739,7 +739,7 @@ public class Job extends AbstractDiffable<Job> implements Writeable, ToXContent
                 throw new IllegalArgumentException(Messages.getMessage(Messages.JOB_CONFIG_ID_TOO_LONG, MAX_JOB_ID_LENGTH));
             }
             if (!PrelertStrings.isValidId(id)) {
-                throw new IllegalArgumentException(Messages.getMessage(Messages.INVALID_ID, ID.getPreferredName()));
+                throw new IllegalArgumentException(Messages.getMessage(Messages.INVALID_ID, ID.getPreferredName(), id));
             }
 
             if (Strings.isNullOrEmpty(indexName)) {
diff --git a/elasticsearch/src/main/resources/org/elasticsearch/xpack/prelert/job/messages/prelert_messages.properties b/elasticsearch/src/main/resources/org/elasticsearch/xpack/prelert/job/messages/prelert_messages.properties
index 1a3c13a9e98..9300c01decc 100644
--- a/elasticsearch/src/main/resources/org/elasticsearch/xpack/prelert/job/messages/prelert_messages.properties
+++ b/elasticsearch/src/main/resources/org/elasticsearch/xpack/prelert/job/messages/prelert_messages.properties
@@ -10,7 +10,7 @@ datastore.error.deleting =  Error deleting index ''{0}''
 datastore.error.deleting.missing.index = Cannot delete job - no index with id ''{0}'' in the database
 datastore.error.executing.script = Error executing script ''{0}''
 
-invalid.id = Invalid {0}; must be lowercase alphanumeric, may contain hyphens or underscores, may not start with underscore
+invalid.id = Invalid {0}; ''{1}'' must be lowercase alphanumeric, may contain hyphens or underscores, may not start with underscore
 
 license.limit.detectors = Cannot create new job - your license limits you to {0,number,integer} detector(s), but you have configured {1,number,integer}.
 license.limit.detectors.reactivate = Cannot reactivate job with id ''{0}'' - your license limits you to {1,number,integer} concurrently running detectors. You must close a job before you can reactivate another.
diff --git a/elasticsearch/src/test/java/org/elasticsearch/xpack/prelert/job/JobTests.java b/elasticsearch/src/test/java/org/elasticsearch/xpack/prelert/job/JobTests.java
index 680b81d953c..0bc1dac5783 100644
--- a/elasticsearch/src/test/java/org/elasticsearch/xpack/prelert/job/JobTests.java
+++ b/elasticsearch/src/test/java/org/elasticsearch/xpack/prelert/job/JobTests.java
@@ -242,9 +242,9 @@ public class JobTests extends AbstractSerializingTestCase<Job> {
     public void testCheckValidId_ProhibitedChars() {
         String invalidChars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ!@#$%^&*()+?\"'~±/\\[]{},<>=";
         Job.Builder builder = buildJobBuilder("foo");
-        String errorMessage = Messages.getMessage(Messages.INVALID_ID, Job.ID.getPreferredName());
         for (char c : invalidChars.toCharArray()) {
             builder.setId(Character.toString(c));
+            String errorMessage = Messages.getMessage(Messages.INVALID_ID, Job.ID.getPreferredName(), Character.toString(c));
             IllegalArgumentException e = expectThrows(IllegalArgumentException.class, builder::build);
             assertEquals(errorMessage, e.getMessage());
         }
@@ -252,14 +252,14 @@ public class JobTests extends AbstractSerializingTestCase<Job> {
 
     public void testCheckValidId_startsWithUnderscore() {
         Job.Builder builder = buildJobBuilder("_foo");
-        String errorMessage = Messages.getMessage(Messages.INVALID_ID, Job.ID.getPreferredName());
+        String errorMessage = Messages.getMessage(Messages.INVALID_ID, Job.ID.getPreferredName(), "_foo");
         IllegalArgumentException e = expectThrows(IllegalArgumentException.class, builder::build);
         assertEquals(errorMessage, e.getMessage());
     }
 
     public void testCheckValidId_endsWithUnderscore() {
         Job.Builder builder = buildJobBuilder("foo_");
-        String errorMessage = Messages.getMessage(Messages.INVALID_ID, Job.ID.getPreferredName());
+        String errorMessage = Messages.getMessage(Messages.INVALID_ID, Job.ID.getPreferredName(), "foo_");
         IllegalArgumentException e = expectThrows(IllegalArgumentException.class, builder::build);
         assertEquals(errorMessage, e.getMessage());
     }