diff --git a/README.md b/README.md
index 6b4bc0ff..64415d31 100644
--- a/README.md
+++ b/README.md
@@ -517,6 +517,8 @@ Options:
               # Pacticipant name
       [--display-name=DISPLAY_NAME]        
               # Display name
+      [--main-branch=MAIN_BRANCH]          
+              # The main development branch of the pacticipant repository
       [--repository-url=REPOSITORY_URL]    
               # The repository URL of the pacticipant
   -o, [--output=OUTPUT]                    
diff --git a/lib/pact_broker/client/cli/pacticipant_commands.rb b/lib/pact_broker/client/cli/pacticipant_commands.rb
index 9d273087..5ea04360 100644
--- a/lib/pact_broker/client/cli/pacticipant_commands.rb
+++ b/lib/pact_broker/client/cli/pacticipant_commands.rb
@@ -2,13 +2,14 @@ module PactBroker
   module Client
     module CLI
       module PacticipantCommands
-        PACTICIPANT_PARAM_NAMES = [:name, :display_name, :repository_url]
+        PACTICIPANT_PARAM_NAMES = [:name, :display_name, :main_branch, :repository_url]
 
         def self.included(thor)
           thor.class_eval do
             desc 'create-or-update-pacticipant', 'Create or update pacticipant by name'
             method_option :name, type: :string, required: true, desc: "Pacticipant name"
             method_option :display_name, type: :string, desc: "Display name"
+            method_option :main_branch, type: :string, required: false, desc: "The main development branch of the pacticipant repository"
             method_option :repository_url, type: :string, required: false, desc: "The repository URL of the pacticipant"
             output_option_json_or_text
             shared_authentication_options
diff --git a/lib/pact_broker/client/pacticipants/create.rb b/lib/pact_broker/client/pacticipants/create.rb
index 7a771255..b7253a8b 100644
--- a/lib/pact_broker/client/pacticipants/create.rb
+++ b/lib/pact_broker/client/pacticipants/create.rb
@@ -38,7 +38,8 @@ def pacticipant_resource_params
           {
             name: params[:name],
             repositoryUrl: params[:repository_url],
-            displayName: params[:display_name]
+            displayName: params[:display_name],
+            mainBranch: params[:main_branch]
           }.compact
         end
       end