diff --git a/lib/nanoc/base/repos/checksum_store.rb b/lib/nanoc/base/repos/checksum_store.rb
index 06ad488976..0b6c093942 100644
--- a/lib/nanoc/base/repos/checksum_store.rb
+++ b/lib/nanoc/base/repos/checksum_store.rb
@@ -6,11 +6,14 @@ module Nanoc::Int
   class ChecksumStore < ::Nanoc::Int::Store
     include Nanoc::Int::ContractsSupport
 
+    attr_accessor :objects
+
     # @param [Nanoc::Int::Site] site
-    def initialize(site: nil)
+    def initialize(site: nil, objects:)
       super(Nanoc::Int::Store.tmp_path_for(env_name: (site.config.env_name if site), store_name: 'checksums'), 1)
 
-      @site = site
+      @site = site # TODO: Remove
+      @objects = objects
 
       @checksums = {}
     end
@@ -53,7 +56,14 @@ def data
     end
 
     def data=(new_data)
-      @checksums = new_data
+      references = Set.new(@objects.map(&:reference))
+
+      @checksums = {}
+      new_data.each_pair do |key, checksum|
+        if references.include?(key) || references.include?(key.first)
+          @checksums[key] = checksum
+        end
+      end
     end
   end
 end
diff --git a/lib/nanoc/base/services/compiler.rb b/lib/nanoc/base/services/compiler.rb
index d88688d809..b4c5d7a6cf 100644
--- a/lib/nanoc/base/services/compiler.rb
+++ b/lib/nanoc/base/services/compiler.rb
@@ -83,9 +83,10 @@ def run
     end
 
     def load_stores
-      # FIXME: icky hack to update the dependency store’s list of objects
+      # FIXME: icky hack to update the dependency/checksum store’s list of objects
       # (does not include preprocessed objects otherwise)
       dependency_store.objects = site.items.to_a + site.layouts.to_a
+      checksum_store.objects = site.items.to_a + site.layouts.to_a + site.code_snippets + [site.config]
 
       stores.each(&:load)
     end
diff --git a/lib/nanoc/base/services/compiler_loader.rb b/lib/nanoc/base/services/compiler_loader.rb
index e7423acc9e..77fde3a413 100644
--- a/lib/nanoc/base/services/compiler_loader.rb
+++ b/lib/nanoc/base/services/compiler_loader.rb
@@ -7,8 +7,10 @@ def load(site, action_provider: nil)
       dependency_store =
         Nanoc::Int::DependencyStore.new(site.items.to_a + site.layouts.to_a, env_name: site.config.env_name)
 
+      objects = site.items.to_a + site.layouts.to_a + site.code_snippets + [site.config]
+
       checksum_store =
-        Nanoc::Int::ChecksumStore.new(site: site)
+        Nanoc::Int::ChecksumStore.new(site: site, objects: objects)
 
       item_rep_repo = Nanoc::Int::ItemRepRepo.new
 
diff --git a/spec/nanoc/base/repos/checksum_store_spec.rb b/spec/nanoc/base/repos/checksum_store_spec.rb
new file mode 100644
index 0000000000..24f8f5a9d6
--- /dev/null
+++ b/spec/nanoc/base/repos/checksum_store_spec.rb
@@ -0,0 +1,133 @@
+describe Nanoc::Int::ChecksumStore do
+  let(:store) { described_class.new(objects: objects) }
+
+  let(:objects) { [item, code_snippet] }
+
+  let(:item) { Nanoc::Int::Item.new('asdf', {}, '/foo.md') }
+  let(:other_item) { Nanoc::Int::Item.new('asdf', {}, '/sneaky.md') }
+
+  let(:code_snippet) { Nanoc::Int::CodeSnippet.new('def hi ; end', 'lib/foo.rb') }
+  let(:other_code_snippet) { Nanoc::Int::CodeSnippet.new('def ho ; end', 'lib/bar.rb') }
+
+  context 'nothing added' do
+    it 'has no checksum' do
+      expect(store[item]).to be_nil
+    end
+
+    it 'has no content checksum' do
+      expect(store.content_checksum_for(item)).to be_nil
+    end
+
+    it 'has no attributes checksum' do
+      expect(store.attributes_checksum_for(item)).to be_nil
+    end
+  end
+
+  context 'setting content on known non-document' do
+    before { store.add(code_snippet) }
+
+    it 'has checksum' do
+      expect(store[code_snippet]).not_to be_nil
+    end
+
+    it 'has no content checksum' do
+      expect(store.content_checksum_for(code_snippet)).to be_nil
+    end
+
+    it 'has no attributes checksum' do
+      expect(store.attributes_checksum_for(code_snippet)).to be_nil
+    end
+
+    context 'after storing and loading' do
+      before do
+        store.store
+        store.load
+      end
+
+      it 'has checksum' do
+        expect(store[code_snippet]).not_to be_nil
+      end
+    end
+  end
+
+  context 'setting content on unknown non-document' do
+    before { store.add(other_code_snippet) }
+
+    it 'has checksum' do
+      expect(store[other_code_snippet]).not_to be_nil
+    end
+
+    it 'has no content checksum' do
+      expect(store.content_checksum_for(other_code_snippet)).to be_nil
+    end
+
+    it 'has no attributes checksum' do
+      expect(store.attributes_checksum_for(other_code_snippet)).to be_nil
+    end
+
+    context 'after storing and loading' do
+      before do
+        store.store
+        store.load
+      end
+
+      it 'has no checksum' do
+        expect(store[other_code_snippet]).to be_nil
+      end
+    end
+  end
+
+  context 'setting content on known item' do
+    before { store.add(item) }
+
+    it 'has checksum' do
+      expect(store[item]).not_to be_nil
+    end
+
+    it 'has content checksum' do
+      expect(store.content_checksum_for(item)).not_to be_nil
+    end
+
+    it 'has attributes checksum' do
+      expect(store.attributes_checksum_for(item)).not_to be_nil
+    end
+
+    context 'after storing and loading' do
+      before do
+        store.store
+        store.load
+      end
+
+      it 'has checksum' do
+        expect(store[item]).not_to be_nil
+      end
+    end
+  end
+
+  context 'setting content on unknown item' do
+    before { store.add(other_item) }
+
+    it 'has checksum' do
+      expect(store[other_item]).not_to be_nil
+    end
+
+    it 'has content checksum' do
+      expect(store.content_checksum_for(other_item)).not_to be_nil
+    end
+
+    it 'has attributes checksum' do
+      expect(store.attributes_checksum_for(other_item)).not_to be_nil
+    end
+
+    context 'after storing and loading' do
+      before do
+        store.store
+        store.load
+      end
+
+      it 'has no checksum' do
+        expect(store[other_item]).to be_nil
+      end
+    end
+  end
+end
diff --git a/spec/nanoc/base/services/outdatedness_checker_spec.rb b/spec/nanoc/base/services/outdatedness_checker_spec.rb
index 95d44a6674..46a76bd63b 100644
--- a/spec/nanoc/base/services/outdatedness_checker_spec.rb
+++ b/spec/nanoc/base/services/outdatedness_checker_spec.rb
@@ -35,6 +35,8 @@
   let(:item_rep) { Nanoc::Int::ItemRep.new(item, :default) }
   let(:item) { Nanoc::Int::Item.new('stuff', {}, '/foo.md') }
 
+  let(:objects) { [item] }
+
   before do
     reps << item_rep
     rule_memory_store[item_rep] = old_memory_for_item_rep.serialize
@@ -45,9 +47,7 @@
   describe '#basic_outdatedness_reason_for' do
     subject { outdatedness_checker.send(:basic_outdatedness_reason_for, obj) }
 
-    let(:checksum_store) do
-      Nanoc::Int::ChecksumStore.new
-    end
+    let(:checksum_store) { Nanoc::Int::ChecksumStore.new(objects: objects) }
 
     let(:config) { Nanoc::Int::Configuration.new }
 
@@ -106,9 +106,7 @@
       Nanoc::Int::DependencyStore.new(objects)
     end
 
-    let(:checksum_store) do
-      Nanoc::Int::ChecksumStore.new
-    end
+    let(:checksum_store) { Nanoc::Int::ChecksumStore.new(objects: objects) }
 
     let(:other_item) { Nanoc::Int::Item.new('other stuff', {}, '/other.md') }
     let(:other_item_rep) { Nanoc::Int::ItemRep.new(other_item, :default) }
diff --git a/spec/nanoc/base/services/outdatedness_rules_spec.rb b/spec/nanoc/base/services/outdatedness_rules_spec.rb
index b287e7122f..235f089ad5 100644
--- a/spec/nanoc/base/services/outdatedness_rules_spec.rb
+++ b/spec/nanoc/base/services/outdatedness_rules_spec.rb
@@ -21,12 +21,13 @@
     let(:site) { double(:site) }
     let(:config) { Nanoc::Int::Configuration.new }
     let(:code_snippets) { [] }
+    let(:objects) { [config] + code_snippets + [item] }
 
     let(:action_provider) { double(:action_provider) }
     let(:reps) { Nanoc::Int::ItemRepRepo.new }
     let(:dependency_store) { Nanoc::Int::DependencyStore.new(dependency_store_objects) }
     let(:rule_memory_store) { Nanoc::Int::RuleMemoryStore.new }
-    let(:checksum_store) { Nanoc::Int::ChecksumStore.new }
+    let(:checksum_store) { Nanoc::Int::ChecksumStore.new(objects: objects) }
 
     let(:dependency_store_objects) { [item] }
 
@@ -317,8 +318,6 @@
         ].map { |c| !c.instance.apply(new_obj, outdatedness_checker) }
       end
 
-      let(:checksum_store) { Nanoc::Int::ChecksumStore.new }
-
       let(:stored_obj) { raise 'override me' }
       let(:new_obj)    { raise 'override me' }
 
diff --git a/test/base/test_checksum_store.rb b/test/base/test_checksum_store.rb
deleted file mode 100644
index a3785b0c30..0000000000
--- a/test/base/test_checksum_store.rb
+++ /dev/null
@@ -1,28 +0,0 @@
-class Nanoc::Int::ChecksumStoreTest < Nanoc::TestCase
-  def test_get_with_existing_object
-    require 'pstore'
-
-    # Create store
-    FileUtils.mkdir_p('tmp')
-    pstore = PStore.new('tmp/checksums')
-    pstore.transaction do
-      pstore[:data] = { [:item, '/moo/'] => 'zomg' }
-      pstore[:version] = 1
-    end
-
-    # Check
-    store = Nanoc::Int::ChecksumStore.new
-    store.load
-    obj = Nanoc::Int::Item.new('Moo?', {}, '/moo/')
-    assert_equal 'zomg', store[obj]
-  end
-
-  def test_get_with_nonexistant_object
-    store = Nanoc::Int::ChecksumStore.new
-    store.load
-
-    # Check
-    obj = Nanoc::Int::Item.new('Moo?', {}, '/animals/cow/')
-    assert_equal nil, store[obj]
-  end
-end
diff --git a/test/base/test_compiler.rb b/test/base/test_compiler.rb
index 5c66e15156..c3c40dac55 100644
--- a/test/base/test_compiler.rb
+++ b/test/base/test_compiler.rb
@@ -11,9 +11,11 @@ def new_compiler(site = nil)
 
     action_provider = Nanoc::Int::ActionProvider.named(:rule_dsl).for(site)
 
+    objects = site.items.to_a + site.layouts.to_a
+
     params = {
       compiled_content_cache: Nanoc::Int::CompiledContentCache.new(items: site.items),
-      checksum_store: Nanoc::Int::ChecksumStore.new(site: site),
+      checksum_store: Nanoc::Int::ChecksumStore.new(site: site, objects: objects),
       rule_memory_store: Nanoc::Int::RuleMemoryStore.new,
       dependency_store: Nanoc::Int::DependencyStore.new(
         site.items.to_a + site.layouts.to_a,