diff --git a/enterprise/app/services/captain/assistant/agent_runner_service.rb b/enterprise/app/services/captain/assistant/agent_runner_service.rb
index 271e201d6..e60260c3d 100644
--- a/enterprise/app/services/captain/assistant/agent_runner_service.rb
+++ b/enterprise/app/services/captain/assistant/agent_runner_service.rb
@@ -122,7 +122,7 @@ class Captain::Assistant::AgentRunnerService
   end
 
   def message_length_limit
-    @message_length_limit ||= Captain::MessageLengthLimit.for(@conversation&.inbox)
+    @message_length_limit ||= Captain::MessageLengthLimit.for(@conversation)
   end
 
   def error_response(error_message)
diff --git a/enterprise/app/services/captain/assistant/runner_state_helper.rb b/enterprise/app/services/captain/assistant/runner_state_helper.rb
index 3b43e5ecc..2ab1b902a 100644
--- a/enterprise/app/services/captain/assistant/runner_state_helper.rb
+++ b/enterprise/app/services/captain/assistant/runner_state_helper.rb
@@ -31,7 +31,7 @@ module Captain::Assistant::RunnerStateHelper
   def build_conversation_state(state)
     state[:conversation] = slice_attrs(@conversation, CONVERSATION_STATE_ATTRIBUTES)
     state[:channel_type] = @conversation.inbox&.channel_type
-    state[:message_length_limit] = Captain::MessageLengthLimit.for(@conversation.inbox)
+    state[:message_length_limit] = Captain::MessageLengthLimit.for(@conversation)
     state[:contact] = slice_attrs(@conversation.contact, CONTACT_STATE_ATTRIBUTES) if @conversation.contact
     state[:campaign] = slice_attrs(@conversation.campaign, CAMPAIGN_STATE_ATTRIBUTES) if @conversation.campaign
     state[:contact_inbox] = slice_attrs(@conversation.contact_inbox, CONTACT_INBOX_STATE_ATTRIBUTES) if @conversation.contact_inbox
diff --git a/enterprise/lib/captain/message_length_limit.rb b/enterprise/lib/captain/message_length_limit.rb
index 0d5918269..11703dfc8 100644
--- a/enterprise/lib/captain/message_length_limit.rb
+++ b/enterprise/lib/captain/message_length_limit.rb
@@ -1,5 +1,6 @@
 class Captain::MessageLengthLimit
   DEFAULT = 10_000
+  INSTAGRAM_DIRECT_MESSAGE = 'instagram_direct_message'.freeze
   CHANNEL_LIMITS = {
     'Channel::FacebookPage' => 2_000,
     'Channel::Instagram' => 1_000,
@@ -14,8 +15,11 @@ class Captain::MessageLengthLimit
     'whatsapp' => 1_600
   }.freeze
 
-  def self.for(inbox)
-    return unless inbox
+  def self.for(conversation)
+    return unless conversation
+
+    inbox = conversation.inbox
+    return CHANNEL_LIMITS.fetch('Channel::Instagram') if conversation.additional_attributes['type'] == INSTAGRAM_DIRECT_MESSAGE
     return TWILIO_LIMITS.fetch(inbox.channel.medium) if inbox.twilio?
 
     CHANNEL_LIMITS.fetch(inbox.channel_type, DEFAULT)