diff --git a/lib/factory_bot/find_definitions.rb b/lib/factory_bot/find_definitions.rb
index bd20ee4..44b970c 100644
--- a/lib/factory_bot/find_definitions.rb
+++ b/lib/factory_bot/find_definitions.rb
@@ -13,12 +13,18 @@ module FactoryBot
     absolute_definition_file_paths = definition_file_paths.map { |path| File.expand_path(path) }
 
     absolute_definition_file_paths.uniq.each do |path|
-      load("#{path}.rb") if File.exist?("#{path}.rb")
+      load_file_or_directory(path)
+    end
+  end
 
-      if File.directory? path
-        Dir[File.join(path, "**", "*.rb")].sort.each do |file|
-          load file
-        end
+  def self.load_file_or_directory(path)
+    load("#{path}.rb") if File.exist?("#{path}.rb")
+
+    load path if File.file? path
+
+    if File.directory? path
+      Dir[File.join(path, "**", "*.rb")].sort.each do |file|
+        load file
       end
     end
   end
diff --git a/spec/factory_bot/find_definitions_spec.rb b/spec/factory_bot/find_definitions_spec.rb
index cb7208d..6c00e5b 100644
--- a/spec/factory_bot/find_definitions_spec.rb
+++ b/spec/factory_bot/find_definitions_spec.rb
@@ -109,4 +109,45 @@ describe "definition loading" do
       end
     end
   end
+
+  describe "definition_file_paths" do
+    in_directory_with_files "spec/my_factories/factory_one.rb", "spec/my_factories/factory_two.rb"
+
+    before { allow(FactoryBot).to receive(:load) }
+
+    it "supports files without extension" do
+      old_paths = FactoryBot.definition_file_paths
+      FactoryBot.definition_file_paths = ["spec/my_factories/factory_one"]
+
+      FactoryBot.find_definitions
+
+      expect(FactoryBot).to have_received(:load).once.with(File.expand_path("spec/my_factories/factory_one.rb"))
+    ensure
+      FactoryBot.definition_file_paths = old_paths
+    end
+
+    it "supports directories" do
+      old_paths = FactoryBot.definition_file_paths
+      FactoryBot.definition_file_paths = ["spec/my_factories"]
+
+      FactoryBot.find_definitions
+
+      expect(FactoryBot).to have_received(:load).twice
+      expect(FactoryBot).to have_received(:load).with(File.expand_path("spec/my_factories/factory_one.rb"))
+      expect(FactoryBot).to have_received(:load).with(File.expand_path("spec/my_factories/factory_two.rb"))
+    ensure
+      FactoryBot.definition_file_paths = old_paths
+    end
+
+    it "supports files with extension" do
+      old_paths = FactoryBot.definition_file_paths
+      FactoryBot.definition_file_paths = ["spec/my_factories/factory_one.rb"]
+
+      FactoryBot.find_definitions
+
+      expect(FactoryBot).to have_received(:load).once.with(File.expand_path("spec/my_factories/factory_one.rb"))
+    ensure
+      FactoryBot.definition_file_paths = old_paths
+    end
+  end
 end