diff --git a/core/src/main/java/org/elasticsearch/action/fieldcaps/TransportFieldCapabilitiesIndexAction.java b/core/src/main/java/org/elasticsearch/action/fieldcaps/TransportFieldCapabilitiesIndexAction.java
index e7db685b4a8..b9e6f56b6d7 100644
--- a/core/src/main/java/org/elasticsearch/action/fieldcaps/TransportFieldCapabilitiesIndexAction.java
+++ b/core/src/main/java/org/elasticsearch/action/fieldcaps/TransportFieldCapabilitiesIndexAction.java
@@ -80,8 +80,10 @@ public class TransportFieldCapabilitiesIndexAction extends TransportSingleShardA
         Map<String, FieldCapabilities> responseMap = new HashMap<>();
         for (String field : fieldNames) {
             MappedFieldType ft = mapperService.fullName(field);
-            FieldCapabilities fieldCap = new FieldCapabilities(field, ft.typeName(), ft.isSearchable(), ft.isAggregatable());
-            responseMap.put(field, fieldCap);
+            if (ft != null) {
+                FieldCapabilities fieldCap = new FieldCapabilities(field, ft.typeName(), ft.isSearchable(), ft.isAggregatable());
+                responseMap.put(field, fieldCap);
+            }
         }
         return new FieldCapabilitiesIndexResponse(shardId.getIndexName(), responseMap);
     }
diff --git a/rest-api-spec/src/main/resources/rest-api-spec/test/field_caps/10_basic.yaml b/rest-api-spec/src/main/resources/rest-api-spec/test/field_caps/10_basic.yaml
index cef72b6e3fe..e6dd5a2c71f 100644
--- a/rest-api-spec/src/main/resources/rest-api-spec/test/field_caps/10_basic.yaml
+++ b/rest-api-spec/src/main/resources/rest-api-spec/test/field_caps/10_basic.yaml
@@ -165,3 +165,45 @@ setup:
   - match: {fields.number.long.indices:                 ["test3"]}
   - is_false: fields.number.long.non_searchable_indices
   - is_false: fields.number.long.non_aggregatable_indices
+
+---
+"Mix in non-existing field field caps":
+  - skip:
+      version: " - 5.4.0"
+      reason:  this bug has been fixed in 5.4.0
+
+  - do:
+      field_caps:
+        index: 'test1,test2,test3'
+        fields: [text, keyword, no_such_field, number, geo]
+
+  - match: {fields.text.text.searchable:                true}
+  - match: {fields.text.text.aggregatable:              false}
+  - is_false: fields.text.text.indices
+  - is_false: fields.text.text.non_searchable_indices
+  - is_false: fields.text.text.non_aggregatable_indices
+  - match: {fields.keyword.keyword.searchable:          true}
+  - match: {fields.keyword.keyword.aggregatable:        true}
+  - is_false: fields.text.keyword.indices
+  - is_false: fields.text.keyword.non_searchable_indices
+  - is_false: fields.text.keyword.non_aggregatable_indices
+  - match: {fields.number.double.searchable:            true}
+  - match: {fields.number.double.aggregatable:          true}
+  - match: {fields.number.double.indices:               ["test1", "test2"]}
+  - is_false: fields.number.double.non_searchable_indices
+  - is_false: fields.number.double.non_aggregatable_indices
+  - match: {fields.number.long.searchable:              true}
+  - match: {fields.number.long.aggregatable:            true}
+  - match: {fields.number.long.indices:                 ["test3"]}
+  - is_false: fields.number.long.non_searchable_indices
+  - is_false: fields.number.long.non_aggregatable_indices
+  - match: {fields.geo.geo_point.searchable:            true}
+  - match: {fields.geo.geo_point.aggregatable:          true}
+  - match: {fields.geo.geo_point.indices:               ["test1", "test2"]}
+  - is_false: fields.geo.geo_point.non_searchable_indices
+  - is_false: fields.geo.geo_point.non_aggregatable_indices
+  - match: {fields.geo.keyword.searchable:              true}
+  - match: {fields.geo.keyword.aggregatable:            true}
+  - match: {fields.geo.keyword.indices:                 ["test3"]}
+  - is_false: fields.geo.keyword.non_searchable_indices
+  - is_false: fields.geo.keyword.on_aggregatable_indices