diff --git a/plugin/src/test/resources/rest-api-spec/test/ml/delete_model_snapshot.yaml b/plugin/src/test/resources/rest-api-spec/test/ml/delete_model_snapshot.yaml
index 78f1a71d78c..81e22cac69c 100644
--- a/plugin/src/test/resources/rest-api-spec/test/ml/delete_model_snapshot.yaml
+++ b/plugin/src/test/resources/rest-api-spec/test/ml/delete_model_snapshot.yaml
@@ -1,4 +1,7 @@
 setup:
+  - skip:
+      features: ["headers"]
+
   - do:
       xpack.ml.put_job:
         job_id: foo
@@ -26,6 +29,9 @@ setup:
         job_id: foo
 
   - do:
+      #set the header so we won't randomize it
+      headers:
+        Content-Type: application/json
       index:
         index:  .ml-anomalies-foo
         type:   model_snapshot
@@ -62,6 +68,9 @@ setup:
           }
 
   - do:
+      #set the header so we won't randomize it
+      headers:
+        Content-Type: application/json
       index:
         index:  .ml-anomalies-foo
         type:   model_snapshot
diff --git a/plugin/src/test/resources/rest-api-spec/test/ml/get_model_snapshots.yaml b/plugin/src/test/resources/rest-api-spec/test/ml/get_model_snapshots.yaml
index b84d13c2a91..e386dae5965 100644
--- a/plugin/src/test/resources/rest-api-spec/test/ml/get_model_snapshots.yaml
+++ b/plugin/src/test/resources/rest-api-spec/test/ml/get_model_snapshots.yaml
@@ -1,4 +1,7 @@
 setup:
+  - skip:
+      features: ["headers"]
+
   - do:
       indices.create:
         index:  .ml-anomalies-foo
@@ -10,6 +13,9 @@ setup:
                   type: date
 
   - do:
+      #set the header so we won't randomize it
+      headers:
+        Content-Type: application/json
       index:
         index:  .ml-anomalies-foo
         type:   model_snapshot
@@ -17,6 +23,9 @@ setup:
         body:   { "job_id": "foo", "snapshot_id": "1", "timestamp": "2016-06-02T00:00:00Z" }
 
   - do:
+      #set the header so we won't randomize it
+      headers:
+        Content-Type: application/json
       index:
         index:  .ml-anomalies-foo
         type:   model_snapshot
diff --git a/plugin/src/test/resources/rest-api-spec/test/ml/jobs_get_stats.yaml b/plugin/src/test/resources/rest-api-spec/test/ml/jobs_get_stats.yaml
index 0a3daf16d14..572ed0307e8 100644
--- a/plugin/src/test/resources/rest-api-spec/test/ml/jobs_get_stats.yaml
+++ b/plugin/src/test/resources/rest-api-spec/test/ml/jobs_get_stats.yaml
@@ -54,8 +54,13 @@ setup:
 
 ---
 "Test get job stats after uploading data prompting the creation of some stats":
+  - skip:
+      features: ["headers"]
 
   - do:
+      #set the header so we won't randomize it
+      headers:
+        Content-Type: application/json
       xpack.ml.post_data:
         job_id: job-stats-test
         body: >
@@ -83,8 +88,13 @@ setup:
 
 ---
 "Test get job stats for closed job":
+  - skip:
+      features: ["headers"]
 
   - do:
+      #set the header so we won't randomize it
+      headers:
+        Content-Type: application/json
       xpack.ml.post_data:
         job_id: job-stats-test
         body: >
diff --git a/plugin/src/test/resources/rest-api-spec/test/ml/post_data.yaml b/plugin/src/test/resources/rest-api-spec/test/ml/post_data.yaml
index 791fc6269d7..ff2813033fb 100644
--- a/plugin/src/test/resources/rest-api-spec/test/ml/post_data.yaml
+++ b/plugin/src/test/resources/rest-api-spec/test/ml/post_data.yaml
@@ -38,7 +38,13 @@ setup:
 
 ---
 "Test POST data job api, flush, close and verify DataCounts doc":
+  - skip:
+      features: ["headers"]
+
   - do:
+      #set the header so we won't randomize it
+      headers:
+        Content-Type: application/json
       xpack.ml.post_data:
         job_id: farequote
         body: >
@@ -105,13 +111,22 @@ setup:
 
 ---
 "Test POST data with invalid parameters":
+  - skip:
+      features: ["headers"]
+
   - do:
+      #set the header so we won't randomize it
+      headers:
+        Content-Type: application/json
       catch: missing
       xpack.ml.post_data:
         job_id: not_a_job
         body: {}
 
   - do:
+      #set the header so we won't randomize it
+      headers:
+        Content-Type: application/json
       catch: /parse_exception/
       xpack.ml.post_data:
         job_id: farequote
@@ -121,6 +136,9 @@ setup:
           {"airline":"JZA","responsetime":"990.4628","sourcetype":"farequote","time":"1403481600"}
 
   - do:
+      #set the header so we won't randomize it
+      headers:
+        Content-Type: application/json
       catch: /parse_exception/
       xpack.ml.post_data:
         job_id: farequote
@@ -168,17 +186,29 @@ setup:
 
 ---
 "Test flushing, posting and closing a closed job":
+  - skip:
+      features: ["headers"]
+
   - do:
+      #set the header so we won't randomize it
+      headers:
+        Content-Type: application/json
       catch: /status_exception/
       xpack.ml.flush_job:
         job_id: closed_job
 
   - do:
+      #set the header so we won't randomize it
+      headers:
+        Content-Type: application/json
       catch: /status_exception/
       xpack.ml.close_job:
         job_id: closed_job
 
   - do:
+      #set the header so we won't randomize it
+      headers:
+        Content-Type: application/json
       catch: /status_exception/
       xpack.ml.post_data:
         job_id: closed_job
diff --git a/plugin/src/test/resources/rest-api-spec/test/ml/update_model_snapshot.yaml b/plugin/src/test/resources/rest-api-spec/test/ml/update_model_snapshot.yaml
index 1f1f8fc8c81..2d548674378 100644
--- a/plugin/src/test/resources/rest-api-spec/test/ml/update_model_snapshot.yaml
+++ b/plugin/src/test/resources/rest-api-spec/test/ml/update_model_snapshot.yaml
@@ -1,4 +1,7 @@
 setup:
+  - skip:
+      features: ["headers"]
+
   - do:
       indices.create:
         index:  .ml-anomalies-foo
@@ -10,6 +13,9 @@ setup:
                   type: date
 
   - do:
+      #set the header so we won't randomize it
+      headers:
+        Content-Type: application/json
       index:
         index:  .ml-anomalies-foo
         type:   model_snapshot
@@ -22,6 +28,9 @@ setup:
           }
 
   - do:
+      #set the header so we won't randomize it
+      headers:
+        Content-Type: application/json
       index:
         index:  .ml-anomalies-foo
         type:   model_snapshot