diff --git a/CHANGELOG.asciidoc b/CHANGELOG.asciidoc
index eeb647153405..86b2b1d30f0a 100644
--- a/CHANGELOG.asciidoc
+++ b/CHANGELOG.asciidoc
@@ -19,6 +19,7 @@ https://github.com/elastic/beats/compare/v6.0.0-beta1...master[Check the HEAD di
 - Fail if removed setting output.X.flush_interval is explicitly configured.
 - Rename the `/usr/bin/beatname.sh` script (e.g. `metricbeat.sh`) to `/usr/bin/beatname`. {pull}4933[4933]
 - Beat does not start if elasticsearch index pattern was modified but not the template name and pattern. {issue}4769[4769]
+- Fail if removed setting output.X.flush_interval is explicitly configured.
 
 *Auditbeat*
 
diff --git a/auditbeat/auditbeat.reference.yml b/auditbeat/auditbeat.reference.yml
index f802d5493639..176176cf2128 100644
--- a/auditbeat/auditbeat.reference.yml
+++ b/auditbeat/auditbeat.reference.yml
@@ -237,11 +237,6 @@ output.elasticsearch:
   # Configure http request timeout before failing an request to Elasticsearch.
   #timeout: 90
 
-  # The number of seconds to wait for new events between two bulk API index requests.
-  # If `bulk_max_size` is reached before this interval expires, addition bulk index
-  # requests are made.
-  #flush_interval: 1s
-
   # Use SSL settings for HTTPS. Default is true.
   #ssl.enabled: true
 
@@ -441,9 +436,6 @@ output.elasticsearch:
   # on error.
   #required_acks: 1
 
-  # The number of seconds to wait for new events between two producer API calls.
-  #flush_interval: 1s
-
   # The configurable ClientID used for logging, debugging, and auditing
   # purposes.  The default is "beats".
   #client_id: beats
diff --git a/filebeat/filebeat.reference.yml b/filebeat/filebeat.reference.yml
index b0c7ace7c0de..dede09865948 100644
--- a/filebeat/filebeat.reference.yml
+++ b/filebeat/filebeat.reference.yml
@@ -628,11 +628,6 @@ output.elasticsearch:
   # Configure http request timeout before failing an request to Elasticsearch.
   #timeout: 90
 
-  # The number of seconds to wait for new events between two bulk API index requests.
-  # If `bulk_max_size` is reached before this interval expires, addition bulk index
-  # requests are made.
-  #flush_interval: 1s
-
   # Use SSL settings for HTTPS. Default is true.
   #ssl.enabled: true
 
@@ -832,9 +827,6 @@ output.elasticsearch:
   # on error.
   #required_acks: 1
 
-  # The number of seconds to wait for new events between two producer API calls.
-  #flush_interval: 1s
-
   # The configurable ClientID used for logging, debugging, and auditing
   # purposes.  The default is "beats".
   #client_id: beats
diff --git a/heartbeat/heartbeat.reference.yml b/heartbeat/heartbeat.reference.yml
index 8b441970e5e7..aeae9cf0b6ab 100644
--- a/heartbeat/heartbeat.reference.yml
+++ b/heartbeat/heartbeat.reference.yml
@@ -386,11 +386,6 @@ output.elasticsearch:
   # Configure http request timeout before failing an request to Elasticsearch.
   #timeout: 90
 
-  # The number of seconds to wait for new events between two bulk API index requests.
-  # If `bulk_max_size` is reached before this interval expires, addition bulk index
-  # requests are made.
-  #flush_interval: 1s
-
   # Use SSL settings for HTTPS. Default is true.
   #ssl.enabled: true
 
@@ -590,9 +585,6 @@ output.elasticsearch:
   # on error.
   #required_acks: 1
 
-  # The number of seconds to wait for new events between two producer API calls.
-  #flush_interval: 1s
-
   # The configurable ClientID used for logging, debugging, and auditing
   # purposes.  The default is "beats".
   #client_id: beats
diff --git a/libbeat/_meta/config.reference.yml b/libbeat/_meta/config.reference.yml
index 0557b3be5090..a7a5fc4687bd 100644
--- a/libbeat/_meta/config.reference.yml
+++ b/libbeat/_meta/config.reference.yml
@@ -172,11 +172,6 @@ output.elasticsearch:
   # Configure http request timeout before failing an request to Elasticsearch.
   #timeout: 90
 
-  # The number of seconds to wait for new events between two bulk API index requests.
-  # If `bulk_max_size` is reached before this interval expires, addition bulk index
-  # requests are made.
-  #flush_interval: 1s
-
   # Use SSL settings for HTTPS. Default is true.
   #ssl.enabled: true
 
@@ -376,9 +371,6 @@ output.elasticsearch:
   # on error.
   #required_acks: 1
 
-  # The number of seconds to wait for new events between two producer API calls.
-  #flush_interval: 1s
-
   # The configurable ClientID used for logging, debugging, and auditing
   # purposes.  The default is "beats".
   #client_id: beats
diff --git a/libbeat/docs/outputconfig.asciidoc b/libbeat/docs/outputconfig.asciidoc
index 751dd55650a8..61ba17df75a5 100644
--- a/libbeat/docs/outputconfig.asciidoc
+++ b/libbeat/docs/outputconfig.asciidoc
@@ -292,12 +292,6 @@ spooler size.
 
 The http request timeout in seconds for the Elasticsearch request. The default is 90.
 
-===== `flush_interval`
-
-The number of seconds to wait for new events between two bulk API index requests.
-If `bulk_max_size` is reached before this interval expires, additional bulk index
-requests are made.
-
 ===== `ssl`
 
 Configuration options for SSL parameters like the certificate authority to use
@@ -731,10 +725,6 @@ The ACK reliability level required from broker. 0=no response, 1=wait for local
 
 Note: If set to 0, no ACKs are returned by Kafka. Messages might be lost silently on error.
 
-===== `flush_interval`
-
-The number of seconds to wait for new events between two producer API calls.
-
 ===== `ssl`
 
 Configuration options for SSL parameters like the root CA for Kafka connections. See
diff --git a/libbeat/outputs/fileout/file.go b/libbeat/outputs/fileout/file.go
index b19096a48bb9..2ec88ccae8fd 100644
--- a/libbeat/outputs/fileout/file.go
+++ b/libbeat/outputs/fileout/file.go
@@ -31,7 +31,6 @@ func makeFileout(
 	}
 
 	// disable bulk support in publisher pipeline
-	cfg.SetInt("flush_interval", -1, -1)
 	cfg.SetInt("bulk_max_size", -1, -1)
 
 	fo := &fileOutput{beat: beat, stats: stats}
diff --git a/libbeat/outputs/logstash/logstash_integration_test.go b/libbeat/outputs/logstash/logstash_integration_test.go
index c23c607fe952..ae6bc4f43179 100644
--- a/libbeat/outputs/logstash/logstash_integration_test.go
+++ b/libbeat/outputs/logstash/logstash_integration_test.go
@@ -148,12 +148,10 @@ func newTestElasticsearchOutput(t *testing.T, test string) *testOutputer {
 	index := testElasticsearchIndex(test)
 	connection := esConnect(t, index)
 
-	flushInterval := 0
 	bulkSize := 0
 	config, _ := common.NewConfigFrom(map[string]interface{}{
 		"hosts":            []string{getElasticsearchHost()},
 		"index":            connection.index,
-		"flush_interval":   &flushInterval,
 		"bulk_max_size":    &bulkSize,
 		"username":         os.Getenv("ES_USER"),
 		"password":         os.Getenv("ES_PASS"),
diff --git a/libbeat/outputs/output_reg.go b/libbeat/outputs/output_reg.go
index a8f176c3defd..e279ec2806eb 100644
--- a/libbeat/outputs/output_reg.go
+++ b/libbeat/outputs/output_reg.go
@@ -4,6 +4,7 @@ import (
 	"fmt"
 
 	"github.com/elastic/beats/libbeat/common"
+	"github.com/elastic/beats/libbeat/common/cfgwarn"
 )
 
 var outputReg = map[string]Factory{}
@@ -42,5 +43,9 @@ func Load(info common.BeatInfo, stats *Stats, name string, config *common.Config
 		return Group{}, fmt.Errorf("output type %v undefined", name)
 	}
 
+	if err := cfgwarn.CheckRemoved5xSetting(config, "flush_interval"); err != nil {
+		return Fail(err)
+	}
+
 	return factory(info, stats, config)
 }
diff --git a/libbeat/tests/system/test_base.py b/libbeat/tests/system/test_base.py
index 0bb8ccd1d966..c328500a57b3 100644
--- a/libbeat/tests/system/test_base.py
+++ b/libbeat/tests/system/test_base.py
@@ -154,7 +154,6 @@ def test_console_output_size_flush(self):
             console={
                 "pretty": "false",
                 "bulk_max_size": 1,
-                "flush_interval": "1h"
             }
         )
 
diff --git a/metricbeat/metricbeat.reference.yml b/metricbeat/metricbeat.reference.yml
index 4af153c3f40f..a99fc0e61078 100644
--- a/metricbeat/metricbeat.reference.yml
+++ b/metricbeat/metricbeat.reference.yml
@@ -592,11 +592,6 @@ output.elasticsearch:
   # Configure http request timeout before failing an request to Elasticsearch.
   #timeout: 90
 
-  # The number of seconds to wait for new events between two bulk API index requests.
-  # If `bulk_max_size` is reached before this interval expires, addition bulk index
-  # requests are made.
-  #flush_interval: 1s
-
   # Use SSL settings for HTTPS. Default is true.
   #ssl.enabled: true
 
@@ -796,9 +791,6 @@ output.elasticsearch:
   # on error.
   #required_acks: 1
 
-  # The number of seconds to wait for new events between two producer API calls.
-  #flush_interval: 1s
-
   # The configurable ClientID used for logging, debugging, and auditing
   # purposes.  The default is "beats".
   #client_id: beats
diff --git a/packetbeat/packetbeat.reference.yml b/packetbeat/packetbeat.reference.yml
index 2bec7ccb6ba4..9a19c371c827 100644
--- a/packetbeat/packetbeat.reference.yml
+++ b/packetbeat/packetbeat.reference.yml
@@ -624,11 +624,6 @@ output.elasticsearch:
   # Configure http request timeout before failing an request to Elasticsearch.
   #timeout: 90
 
-  # The number of seconds to wait for new events between two bulk API index requests.
-  # If `bulk_max_size` is reached before this interval expires, addition bulk index
-  # requests are made.
-  #flush_interval: 1s
-
   # Use SSL settings for HTTPS. Default is true.
   #ssl.enabled: true
 
@@ -828,9 +823,6 @@ output.elasticsearch:
   # on error.
   #required_acks: 1
 
-  # The number of seconds to wait for new events between two producer API calls.
-  #flush_interval: 1s
-
   # The configurable ClientID used for logging, debugging, and auditing
   # purposes.  The default is "beats".
   #client_id: beats
diff --git a/winlogbeat/winlogbeat.reference.yml b/winlogbeat/winlogbeat.reference.yml
index d2407689e328..8f900c8da6fb 100644
--- a/winlogbeat/winlogbeat.reference.yml
+++ b/winlogbeat/winlogbeat.reference.yml
@@ -201,11 +201,6 @@ output.elasticsearch:
   # Configure http request timeout before failing an request to Elasticsearch.
   #timeout: 90
 
-  # The number of seconds to wait for new events between two bulk API index requests.
-  # If `bulk_max_size` is reached before this interval expires, addition bulk index
-  # requests are made.
-  #flush_interval: 1s
-
   # Use SSL settings for HTTPS. Default is true.
   #ssl.enabled: true
 
@@ -405,9 +400,6 @@ output.elasticsearch:
   # on error.
   #required_acks: 1
 
-  # The number of seconds to wait for new events between two producer API calls.
-  #flush_interval: 1s
-
   # The configurable ClientID used for logging, debugging, and auditing
   # purposes.  The default is "beats".
   #client_id: beats