diff --git a/app/controllers/protocols_controller.rb b/app/controllers/protocols_controller.rb
index b27525c2c..876a1d6e6 100644
--- a/app/controllers/protocols_controller.rb
+++ b/app/controllers/protocols_controller.rb
@@ -231,7 +231,7 @@ class ProtocolsController < ApplicationController
           escape_input(keyword)
         end
       end
-      if @protocol.update_keywords(params[:keywords])
+      if @protocol.update_keywords(params[:keywords], current_user)
         format.json do
           log_activity(:edit_keywords_in_protocol_repository, nil, protocol: @protocol.id)
           render json: @protocol, serializer: ProtocolSerializer, user: current_user
@@ -243,7 +243,7 @@ class ProtocolsController < ApplicationController
   end
 
   def update_authors
-    if @protocol.update(authors: params.require(:protocol)[:authors])
+    if @protocol.update(authors: params.require(:protocol)[:authors], last_modified_by: current_user)
       log_activity(:edit_authors_in_protocol_repository, nil, protocol: @protocol.id)
       render json: @protocol, serializer: ProtocolSerializer, user: current_user
     else
@@ -252,7 +252,7 @@ class ProtocolsController < ApplicationController
   end
 
   def update_name
-    if @protocol.update(name: params.require(:protocol)[:name])
+    if @protocol.update(name: params.require(:protocol)[:name], last_modified_by: current_user)
       log_activity(:edit_protocol_name_in_repository, nil, protocol: @protocol.id)
       render json: {}, status: :ok
     else
@@ -264,7 +264,7 @@ class ProtocolsController < ApplicationController
     old_description = @protocol.description
     respond_to do |format|
       format.json do
-        if @protocol.update(description: params.require(:protocol)[:description])
+        if @protocol.update(description: params.require(:protocol)[:description], last_modified_by: current_user)
           log_activity(:edit_description_in_protocol_repository, nil, protocol: @protocol.id)
           TinyMceAsset.update_images(@protocol, params[:tiny_mce_images], current_user)
           protocol_annotation_notification(old_description)
@@ -285,6 +285,7 @@ class ProtocolsController < ApplicationController
     @protocol.record_timestamps = false
     @protocol.created_at = ts
     @protocol.updated_at = ts
+    @protocol.last_modified_by = current_user
 
     if @protocol.save
       log_activity(:create_protocol_in_repository, nil, protocol: @protocol.id)
diff --git a/app/models/protocol.rb b/app/models/protocol.rb
index e6e7c03c7..0e705e031 100644
--- a/app/models/protocol.rb
+++ b/app/models/protocol.rb
@@ -474,7 +474,7 @@ class Protocol < ApplicationRecord
     result
   end
 
-  def update_keywords(keywords)
+  def update_keywords(keywords, user)
     result = true
     begin
       Protocol.transaction do
@@ -487,6 +487,7 @@ class Protocol < ApplicationRecord
             kw = ProtocolKeyword.find_or_create_by(name: kw_name, team: team)
             protocol_keywords << kw
           end
+          update(last_modified_by: user)
         end
       end
     rescue StandardError
@@ -537,6 +538,7 @@ class Protocol < ApplicationRecord
     self.updated_at = source.published_on
     self.parent_updated_at = source.published_on
     self.added_by = current_user
+    self.last_modified_by = current_user
     self.parent = source
     self.linked_at = Time.zone.now
     save!
@@ -559,6 +561,7 @@ class Protocol < ApplicationRecord
     self.parent = source
     self.parent_updated_at = source.published_on
     self.added_by = current_user
+    self.last_modified_by = current_user
     self.linked_at = Time.zone.now
     self.protocol_type = Protocol.protocol_types[:linked]
     save!
@@ -568,6 +571,7 @@ class Protocol < ApplicationRecord
     clone.team = team
     clone.protocol_type = :in_repository_draft
     clone.added_by = current_user
+    clone.last_modified_by = current_user
     # Don't proceed further if clone is invalid
     return clone if clone.invalid?
 
@@ -590,6 +594,7 @@ class Protocol < ApplicationRecord
     draft.published_on = nil
     draft.version_comment = nil
     draft.previous_version = self
+    draft.last_modified_by = current_user
 
     return draft if draft.invalid?
 
@@ -622,6 +627,7 @@ class Protocol < ApplicationRecord
       authors: authors,
       description: description,
       added_by: current_user,
+      last_modified_by: current_user,
       team: team,
       protocol_type: :in_repository_draft,
       skip_user_assignments: true
diff --git a/app/models/step.rb b/app/models/step.rb
index 344416d79..f8bd376e6 100644
--- a/app/models/step.rb
+++ b/app/models/step.rb
@@ -187,6 +187,7 @@ class Step < ApplicationRecord
     return if saved_changes.keys.sort == %w(completed completed_on updated_at)
 
     # rubocop:disable Rails/SkipsModelValidations
+    protocol.update(last_modified_by: last_modified_by) if last_modified_by
     protocol.touch
     # rubocop:enable Rails/SkipsModelValidations
   end