diff --git a/x-pack/plugin/rollup/src/main/java/org/elasticsearch/xpack/rollup/action/TransportPutRollupJobAction.java b/x-pack/plugin/rollup/src/main/java/org/elasticsearch/xpack/rollup/action/TransportPutRollupJobAction.java
index 9f20fba8e92da..f0600d80f82a6 100644
--- a/x-pack/plugin/rollup/src/main/java/org/elasticsearch/xpack/rollup/action/TransportPutRollupJobAction.java
+++ b/x-pack/plugin/rollup/src/main/java/org/elasticsearch/xpack/rollup/action/TransportPutRollupJobAction.java
@@ -158,7 +158,8 @@ static void updateMapping(RollupJob job, ActionListener<AcknowledgedResponse> li
             MappingMetaData mappings = getMappingResponse.getMappings().get(indexName).get(RollupField.TYPE_NAME);
             Object m = mappings.getSourceAsMap().get("_meta");
             if (m == null) {
-                String msg = "Expected to find _meta key in mapping of rollup index [" + indexName + "] but not found.";
+                String msg = "Rollup data cannot be added to existing indices that contain non-rollup data (expected " +
+                    "to find _meta key in mapping of rollup index [" + indexName + "] but not found).";
                 logger.error(msg);
                 listener.onFailure(new RuntimeException(msg));
                 return;
@@ -166,8 +167,9 @@ static void updateMapping(RollupJob job, ActionListener<AcknowledgedResponse> li
 
             Map<String, Object> metadata = (Map<String, Object>) m;
             if (metadata.get(RollupField.ROLLUP_META) == null) {
-                String msg = "Expected to find rollup meta key [" + RollupField.ROLLUP_META + "] in mapping of rollup index [" + indexName
-                        + "] but not found.";
+                String msg = "Rollup data cannot be added to existing indices that contain non-rollup data (expected " +
+                    "to find rollup meta key [" + RollupField.ROLLUP_META + "] in mapping of rollup index ["
+                    + indexName + "] but not found).";
                 logger.error(msg);
                 listener.onFailure(new RuntimeException(msg));
                 return;
diff --git a/x-pack/plugin/rollup/src/test/java/org/elasticsearch/xpack/rollup/action/PutJobStateMachineTests.java b/x-pack/plugin/rollup/src/test/java/org/elasticsearch/xpack/rollup/action/PutJobStateMachineTests.java
index 5599c50321cf1..3d346456ea98d 100644
--- a/x-pack/plugin/rollup/src/test/java/org/elasticsearch/xpack/rollup/action/PutJobStateMachineTests.java
+++ b/x-pack/plugin/rollup/src/test/java/org/elasticsearch/xpack/rollup/action/PutJobStateMachineTests.java
@@ -180,8 +180,9 @@ public void testNoMetadataInMapping() {
         ActionListener<AcknowledgedResponse> testListener = ActionListener.wrap(response -> {
             fail("Listener success should not have been triggered.");
         }, e -> {
-            assertThat(e.getMessage(), equalTo("Expected to find _meta key in mapping of rollup index ["
-                + job.getConfig().getRollupIndex() + "] but not found."));
+            assertThat(e.getMessage(), equalTo("Rollup data cannot be added to existing indices that contain " +
+                "non-rollup data (expected to find _meta key in mapping of rollup index ["
+                + job.getConfig().getRollupIndex() + "] but not found)."));
         });
 
         Logger logger = mock(Logger.class);
@@ -206,6 +207,44 @@ public void testNoMetadataInMapping() {
         verify(client).execute(eq(GetMappingsAction.INSTANCE), any(GetMappingsRequest.class), any());
     }
 
+    @SuppressWarnings("unchecked")
+    public void testMetadataButNotRollup() {
+        RollupJob job = new RollupJob(ConfigTestHelpers.randomRollupJobConfig(random()), Collections.emptyMap());
+
+        ActionListener<AcknowledgedResponse> testListener = ActionListener.wrap(response -> {
+            fail("Listener success should not have been triggered.");
+        }, e -> {
+            assertThat(e.getMessage(), equalTo("Rollup data cannot be added to existing indices that contain " +
+                "non-rollup data (expected to find rollup meta key [_rollup] in mapping of rollup index ["
+                + job.getConfig().getRollupIndex() + "] but not found)."));
+        });
+
+        Logger logger = mock(Logger.class);
+        Client client = mock(Client.class);
+
+        ArgumentCaptor<ActionListener> requestCaptor = ArgumentCaptor.forClass(ActionListener.class);
+        doAnswer(invocation -> {
+            GetMappingsResponse response = mock(GetMappingsResponse.class);
+            Map<String, Object> m = new HashMap<>(2);
+            m.put("random",
+                Collections.singletonMap(job.getConfig().getId(), job.getConfig()));
+            MappingMetaData meta = new MappingMetaData(RollupField.TYPE_NAME,
+                Collections.singletonMap("_meta", m));
+            ImmutableOpenMap.Builder<String, MappingMetaData> builder = ImmutableOpenMap.builder(1);
+            builder.put(RollupField.TYPE_NAME, meta);
+
+            ImmutableOpenMap.Builder<String, ImmutableOpenMap<String, MappingMetaData>> builder2 = ImmutableOpenMap.builder(1);
+            builder2.put(job.getConfig().getRollupIndex(), builder.build());
+
+            when(response.getMappings()).thenReturn(builder2.build());
+            requestCaptor.getValue().onResponse(response);
+            return null;
+        }).when(client).execute(eq(GetMappingsAction.INSTANCE), any(GetMappingsRequest.class), requestCaptor.capture());
+
+        TransportPutRollupJobAction.updateMapping(job, testListener, mock(PersistentTasksService.class), client, logger);
+        verify(client).execute(eq(GetMappingsAction.INSTANCE), any(GetMappingsRequest.class), any());
+    }
+
     @SuppressWarnings("unchecked")
     public void testNoMappingVersion() {
         RollupJob job = new RollupJob(ConfigTestHelpers.randomRollupJobConfig(random()), Collections.emptyMap());
diff --git a/x-pack/plugin/src/test/resources/rest-api-spec/test/rollup/put_job.yml b/x-pack/plugin/src/test/resources/rest-api-spec/test/rollup/put_job.yml
index 516be25be2a2d..23df0c5837700 100644
--- a/x-pack/plugin/src/test/resources/rest-api-spec/test/rollup/put_job.yml
+++ b/x-pack/plugin/src/test/resources/rest-api-spec/test/rollup/put_job.yml
@@ -128,6 +128,38 @@ setup:
             ]
           }
 
+---
+"Test put_job in non-rollup index":
+  - do:
+      indices.create:
+        index: non-rollup
+  - do:
+      catch: /foo/
+      headers:
+        Authorization: "Basic eF9wYWNrX3Jlc3RfdXNlcjp4LXBhY2stdGVzdC1wYXNzd29yZA==" # run as x_pack_rest_user, i.e. the test setup superuser
+      xpack.rollup.put_job:
+        id: foo
+        body:  >
+          {
+            "index_pattern": "foo",
+            "rollup_index": "non-rollup",
+            "cron": "*/30 * * * * ?",
+            "page_size" :10,
+            "groups" : {
+              "date_histogram": {
+                "field": "the_field",
+                "interval": "1h"
+              }
+            },
+            "metrics": [
+              {
+                "field": "value_field",
+                "metrics": ["min", "max", "sum"]
+              }
+            ]
+          }
+
+
 ---
 "Try to include headers":