diff --git a/plugin/core/src/main/java/org/elasticsearch/xpack/ml/job/config/Detector.java b/plugin/core/src/main/java/org/elasticsearch/xpack/ml/job/config/Detector.java
index 7020dfec7b9..214f55fa584 100644
--- a/plugin/core/src/main/java/org/elasticsearch/xpack/ml/job/config/Detector.java
+++ b/plugin/core/src/main/java/org/elasticsearch/xpack/ml/job/config/Detector.java
@@ -767,8 +767,7 @@ public class Detector implements ToXContentObject, Writeable {
         }
 
         public List<String> extractAnalysisFields() {
-            List<String> analysisFields = Arrays.asList(byFieldName,
-                    overFieldName, partitionFieldName);
+            List<String> analysisFields = Arrays.asList(byFieldName, overFieldName, partitionFieldName);
             return analysisFields.stream().filter(item -> item != null).collect(Collectors.toList());
         }
 
@@ -800,8 +799,21 @@ public class Detector implements ToXContentObject, Writeable {
         private void checkScoping(DetectionRule rule) throws ElasticsearchParseException {
             String targetFieldName = rule.getTargetFieldName();
             checkTargetFieldNameIsValid(extractAnalysisFields(), targetFieldName);
-            List<String> validOptions = getValidFieldNameOptions(rule);
             for (RuleCondition condition : rule.getConditions()) {
+                List<String> validOptions = Collections.emptyList();
+                switch (condition.getType()) {
+                    case CATEGORICAL:
+                        validOptions = extractAnalysisFields();
+                        break;
+                    case NUMERICAL_ACTUAL:
+                    case NUMERICAL_TYPICAL:
+                    case NUMERICAL_DIFF_ABS:
+                        validOptions = getValidFieldNameOptionsForNumeric(rule);
+                        break;
+                    case TIME:
+                    default:
+                        break;
+                }
                 if (!validOptions.contains(condition.getFieldName())) {
                     String msg = Messages.getMessage(Messages.JOB_CONFIG_DETECTION_RULE_CONDITION_INVALID_FIELD_NAME, validOptions,
                             condition.getFieldName());
@@ -819,7 +831,7 @@ public class Detector implements ToXContentObject, Writeable {
             }
         }
 
-        private List<String> getValidFieldNameOptions(DetectionRule rule) {
+        private List<String> getValidFieldNameOptionsForNumeric(DetectionRule rule) {
             List<String> result = new ArrayList<>();
             if (overFieldName != null) {
                 result.add(byFieldName == null ? overFieldName : byFieldName);
diff --git a/plugin/src/test/java/org/elasticsearch/xpack/ml/job/config/DetectorTests.java b/plugin/src/test/java/org/elasticsearch/xpack/ml/job/config/DetectorTests.java
index ed47b3df599..af25bbccf0e 100644
--- a/plugin/src/test/java/org/elasticsearch/xpack/ml/job/config/DetectorTests.java
+++ b/plugin/src/test/java/org/elasticsearch/xpack/ml/job/config/DetectorTests.java
@@ -535,6 +535,38 @@ public class DetectorTests extends AbstractSerializingTestCase<Detector> {
         detector.build();
     }
 
+    public void testVerify_GivenCategoricalRuleOnAllPartitioningFields() {
+        Detector.Builder detector = new Detector.Builder("count", null);
+        detector.setPartitionFieldName("my_partition");
+        detector.setOverFieldName("my_over");
+        detector.setByFieldName("my_by");
+        DetectionRule rule = new DetectionRule.Builder(Arrays.asList(
+                RuleCondition.createCategorical("my_partition", "my_filter_id"),
+                RuleCondition.createCategorical("my_over", "my_filter_id"),
+                RuleCondition.createCategorical("my_by", "my_filter_id")
+        )).build();
+        detector.setRules(Collections.singletonList(rule));
+
+        detector.build();
+    }
+
+    public void testVerify_GivenCategoricalRuleOnInvalidField() {
+        Detector.Builder detector = new Detector.Builder("mean", "my_metric");
+        detector.setPartitionFieldName("my_partition");
+        detector.setOverFieldName("my_over");
+        detector.setByFieldName("my_by");
+        DetectionRule rule = new DetectionRule.Builder(Collections.singletonList(
+                RuleCondition.createCategorical("my_metric", "my_filter_id")
+        )).build();
+        detector.setRules(Collections.singletonList(rule));
+
+        ElasticsearchException e = ESTestCase.expectThrows(ElasticsearchException.class, detector::build);
+
+        assertEquals(Messages.getMessage(Messages.JOB_CONFIG_DETECTION_RULE_CONDITION_INVALID_FIELD_NAME,
+                "[my_by, my_over, my_partition]", "my_metric"),
+                e.getMessage());
+    }
+
     public void testVerify_GivenSameByAndPartition() {
         Detector.Builder detector = new Detector.Builder("count", "");
         detector.setByFieldName("x");
diff --git a/plugin/src/test/resources/rest-api-spec/test/ml/filter_crud.yml b/plugin/src/test/resources/rest-api-spec/test/ml/filter_crud.yml
index 28d215d8cd3..5203ead3ce8 100644
--- a/plugin/src/test/resources/rest-api-spec/test/ml/filter_crud.yml
+++ b/plugin/src/test/resources/rest-api-spec/test/ml/filter_crud.yml
@@ -151,12 +151,13 @@ setup:
             "description":"Analysis of response time by airline",
             "analysis_config" : {
                 "bucket_span": "3600s",
-                "detectors" :[{"function":"mean","field_name":"airline",
+                "detectors" :[{"function":"mean","field_name":"responsetime", "by_field_name": "airline",
                   "rules": [
                     {
                       "conditions": [
                         {
                           "type": "categorical",
+                          "field_name": "airline",
                           "filter_id": "filter-foo"
                         }
                       ]