diff --git a/activerecord/test/cases/adapters/mysql2/explain_test.rb b/activerecord/test/cases/adapters/mysql2/explain_test.rb
index b8e778f0b0..2ad8d4cfcf 100644
--- a/activerecord/test/cases/adapters/mysql2/explain_test.rb
+++ b/activerecord/test/cases/adapters/mysql2/explain_test.rb
@@ -5,7 +5,7 @@ require "models/author"
 require "models/post"
 
 class Mysql2ExplainTest < ActiveRecord::Mysql2TestCase
-  fixtures :authors
+  fixtures :authors, :author_addresses
 
   def test_explain_for_one_query
     explain = Author.where(id: 1).explain
diff --git a/activerecord/test/cases/adapters/postgresql/explain_test.rb b/activerecord/test/cases/adapters/postgresql/explain_test.rb
index be525383e9..c66d66e0a6 100644
--- a/activerecord/test/cases/adapters/postgresql/explain_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/explain_test.rb
@@ -5,7 +5,7 @@ require "models/author"
 require "models/post"
 
 class PostgreSQLExplainTest < ActiveRecord::PostgreSQLTestCase
-  fixtures :authors
+  fixtures :authors, :author_addresses
 
   def test_explain_for_one_query
     explain = Author.where(id: 1).explain
diff --git a/activerecord/test/cases/adapters/sqlite3/explain_test.rb b/activerecord/test/cases/adapters/sqlite3/explain_test.rb
index c7a5204b9e..9711410f1b 100644
--- a/activerecord/test/cases/adapters/sqlite3/explain_test.rb
+++ b/activerecord/test/cases/adapters/sqlite3/explain_test.rb
@@ -5,7 +5,7 @@ require "models/author"
 require "models/post"
 
 class SQLite3ExplainTest < ActiveRecord::SQLite3TestCase
-  fixtures :authors
+  fixtures :authors, :author_addresses
 
   def test_explain_for_one_query
     explain = Author.where(id: 1).explain