diff --git a/lib/linters/default.rb b/lib/linters/default.rb
index e69de29b..28a5fa68 100644
--- a/lib/linters/default.rb
+++ b/lib/linters/default.rb
@@ -0,0 +1,5 @@
+module Linters
+  module Default
+
+  end
+end
diff --git a/lib/tasks/fetch/projects.rake b/lib/tasks/fetch/projects.rake
index 27d7d9da..c67528f5 100644
--- a/lib/tasks/fetch/projects.rake
+++ b/lib/tasks/fetch/projects.rake
@@ -23,6 +23,8 @@ namespace :fetch do
     puts "Parsing projects into #{Vars::Projects.yml_file}"
     Utils.write_to_file(data.to_yaml, Vars::Projects.yml_file)
 
+    Rake::Task["lint:projects"].invoke
+
     sh "bundle exec jekyll pagemaster projects --force"
     sh "bundle exec jekyll pagemaster project_tags --force"
   end
diff --git a/lib/tasks/lint/all.rake b/lib/tasks/lint/all.rake
deleted file mode 100644
index 8ef0b4ce..00000000
--- a/lib/tasks/lint/all.rake
+++ /dev/null
@@ -1,6 +0,0 @@
-namespace :lint do
-  desc 'lint all the fetched yaml data'
-  task :all do
-    puts 'here'
-  end
-end
diff --git a/lib/tasks/lint/courses.rake b/lib/tasks/lint/courses.rake
deleted file mode 100644
index e69de29b..00000000
diff --git a/lib/tasks/lint/people.rake b/lib/tasks/lint/people.rake
deleted file mode 100644
index e69de29b..00000000
diff --git a/lib/tasks/lint/projects.rake b/lib/tasks/lint/projects.rake
index e69de29b..93a753d2 100644
--- a/lib/tasks/lint/projects.rake
+++ b/lib/tasks/lint/projects.rake
@@ -0,0 +1,20 @@
+require 'rainbow'
+require 'linters/default'
+require 'linters/projects'
+require 'vars'
+require 'yaml'
+
+namespace :lint do
+  desc 'lint the fetched project yaml data'
+  task :projects do
+    categories = %w(DH Seed Grant Recipient Grad Fellowship Project Other)
+    people     = YAML.load_file(Vars::People.yml_file).map { |h| h['pid'] }
+    projects   = YAML.load_file Vars::Projects.yml_file
+
+    projects.each do |project|
+      project.dig('pis').each do |pi|
+        puts Rainbow("WARNING: Project '#{project['pid']}' references nonexisting person '#{pi}'.").magenta unless people.include? pi
+      end
+    end
+  end
+end
diff --git a/lib/utils.rb b/lib/utils.rb
index 00875ed1..2393ecbe 100644
--- a/lib/utils.rb
+++ b/lib/utils.rb
@@ -1,7 +1,5 @@
 require 'csv'
 require 'fileutils'
-require 'json'
-require 'yaml'
 
 module Utils
   def self.wget_sheet(sheet_key, csv_file)
@@ -13,7 +11,6 @@ def self.csv_open(file)
     CSV.open(file, headers: :first_row).map(&:to_h)
   end
 
-
   def self.write_to_file(content, file)
     FileUtils.mkdir_p File.dirname(file)
     File.open(file, "w") { |f| f.write content }