diff --git a/lib/docs/core/models/entry.rb b/lib/docs/core/models/entry.rb
index 7d5a404d..9e5c6282 100644
--- a/lib/docs/core/models/entry.rb
+++ b/lib/docs/core/models/entry.rb
@@ -1,11 +1,21 @@
+# frozen_string_literal: true
+
 module Docs
   class Entry
+    class Invalid < StandardError; end
+
     attr_accessor :name, :type, :path
 
     def initialize(name = nil, path = nil, type = nil)
       self.name = name
       self.path = path
       self.type = type
+
+      unless root?
+        raise Invalid, 'missing name' if !name || name.empty?
+        raise Invalid, 'missing path' if !path || path.empty?
+        raise Invalid, 'missing type' if !type || type.empty?
+      end
     end
 
     def ==(other)
diff --git a/test/lib/docs/core/doc_test.rb b/test/lib/docs/core/doc_test.rb
index 2316ce8e..8c3937e2 100644
--- a/test/lib/docs/core/doc_test.rb
+++ b/test/lib/docs/core/doc_test.rb
@@ -14,7 +14,7 @@ class DocsDocTest < MiniTest::Spec
   end
 
   let :entry do
-    Docs::Entry.new
+    Docs::Entry.new 'name', 'path', 'type'
   end
 
   let :store do
@@ -262,7 +262,7 @@ class DocsDocTest < MiniTest::Spec
           mock(store).write('index.json', anything) do |path, json|
             json = JSON.parse(json)
             assert_equal pages.length, json['entries'].length
-            assert_includes json['entries'], Docs::Entry.new('one').as_json.stringify_keys
+            assert_includes json['entries'], Docs::Entry.new('one', 'path', 'type').as_json.stringify_keys
           end
           doc.store_pages(store)
         end
diff --git a/test/lib/docs/core/models/entry_test.rb b/test/lib/docs/core/models/entry_test.rb
index bbf811ff..d5258910 100644
--- a/test/lib/docs/core/models/entry_test.rb
+++ b/test/lib/docs/core/models/entry_test.rb
@@ -5,20 +5,35 @@ class DocsEntryTest < MiniTest::Spec
   Entry = Docs::Entry
 
   let :entry do
-    Entry.new
+    Entry.new('name', 'path', 'type')
+  end
+
+  def build_entry(name = 'name', path = 'path', type = 'type')
+    Entry.new(name, path, type)
   end
 
   describe ".new" do
-    it "stores a name" do
-      assert_equal 'name', Entry.new('name').name
+    it "stores #name, #path and #type" do
+      entry = Entry.new('name', 'path', 'type')
+      assert_equal 'name', entry.name
+      assert_equal 'path', entry.path
+      assert_equal 'type', entry.type
     end
 
-    it "stores a path" do
-      assert_equal 'path', Entry.new(nil, 'path').path
+    it "raises an error when #name, #path or #type is nil or empty" do
+      assert_raises(Docs::Entry::Invalid) { Entry.new(nil, 'path', 'type') }
+      assert_raises(Docs::Entry::Invalid) { Entry.new('', 'path', 'type') }
+      assert_raises(Docs::Entry::Invalid) { Entry.new('name', nil, 'type') }
+      assert_raises(Docs::Entry::Invalid) { Entry.new('name', '', 'type') }
+      assert_raises(Docs::Entry::Invalid) { Entry.new('name', 'path', nil) }
+      assert_raises(Docs::Entry::Invalid) { Entry.new('name', 'path', '') }
     end
 
-    it "stores a type" do
-      assert_equal 'type', Entry.new(nil, nil, 'type').type
+    it "don't raise an error when #path is 'index' and #name or #type is nil or empty" do
+      Entry.new(nil, 'index', 'type')
+      Entry.new('', 'index', 'type')
+      Entry.new('name', 'index', nil)
+      Entry.new('name', 'index', '')
     end
   end
 
@@ -48,40 +63,40 @@ class DocsEntryTest < MiniTest::Spec
 
   describe "#==" do
     it "returns true when the other has the same name, path and type" do
-      assert_equal Entry.new, Entry.new
+      assert_equal build_entry, build_entry
     end
 
     it "returns false when the other has a different name" do
-      entry.name = 'name'
-      refute_equal Entry.new, entry
+      entry.name = 'other_name'
+      refute_equal build_entry, entry
     end
 
     it "returns false when the other has a different path" do
-      entry.path = 'path'
-      refute_equal Entry.new, entry
+      entry.path = 'other_path'
+      refute_equal build_entry, entry
     end
 
     it "returns false when the other has a different type" do
-      entry.type = 'type'
-      refute_equal Entry.new, entry
+      entry.type = 'other_type'
+      refute_equal build_entry, entry
     end
   end
 
   describe "#<=>" do
     it "returns 1 when the other's name is less" do
-      assert_equal 1, Entry.new('b') <=> Entry.new('a')
+      assert_equal 1, build_entry('b') <=> build_entry('a')
     end
 
     it "returns -1 when the other's name is greater" do
-      assert_equal -1, Entry.new('a') <=> Entry.new('b')
+      assert_equal -1, build_entry('a') <=> build_entry('b')
     end
 
     it "returns 0 when the other's name is equal" do
-      assert_equal 0, Entry.new('a') <=> Entry.new('a')
+      assert_equal 0, build_entry('a') <=> build_entry('a')
     end
 
     it "is case-insensitive" do
-      assert_equal 0, Entry.new('a') <=> Entry.new('A')
+      assert_equal 0, build_entry('a') <=> build_entry('A')
     end
   end