diff --git a/lib/jekyll/configuration.rb b/lib/jekyll/configuration.rb
index 196cf587..8dc1807d 100644
--- a/lib/jekyll/configuration.rb
+++ b/lib/jekyll/configuration.rb
@@ -17,7 +17,9 @@ module Jekyll
       # Handling Reading
       "safe"              => false,
       "include"           => [".htaccess"],
-      "exclude"           => %w(node_modules vendor),
+      "exclude"           => %w(
+        node_modules vendor/bundle/ vendor/cache/ vendor/gems/ vendor/ruby/
+      ),
       "keep_files"        => [".git", ".svn"],
       "encoding"          => "utf-8",
       "markdown_ext"      => "markdown,mkdown,mkdn,mkd,md",
diff --git a/lib/jekyll/entry_filter.rb b/lib/jekyll/entry_filter.rb
index 6063607e..5f3431d8 100644
--- a/lib/jekyll/entry_filter.rb
+++ b/lib/jekyll/entry_filter.rb
@@ -36,8 +36,7 @@ module Jekyll
     end
 
     def included?(entry)
-      glob_include?(site.include,
-        entry)
+      glob_include?(site.include, entry)
     end
 
     def special?(entry)
@@ -50,14 +49,14 @@ module Jekyll
     end
 
     def excluded?(entry)
-      excluded = glob_include?(site.exclude, relative_to_source(entry))
-      if excluded
-        Jekyll.logger.debug(
-          "EntryFilter:",
-          "excluded #{relative_to_source(entry)}"
-        )
+      glob_include?(site.exclude, relative_to_source(entry)).tap do |excluded|
+        if excluded
+          Jekyll.logger.debug(
+            "EntryFilter:",
+            "excluded #{relative_to_source(entry)}"
+          )
+        end
       end
-      excluded
     end
 
     # --
diff --git a/test/test_configuration.rb b/test/test_configuration.rb
index b0b34cce..696fc3e9 100644
--- a/test/test_configuration.rb
+++ b/test/test_configuration.rb
@@ -52,6 +52,14 @@ class TestConfiguration < JekyllUnitTest
     should "exclude node_modules" do
       assert_includes Configuration.from({})["exclude"], "node_modules"
     end
+
+    should "exclude ruby vendor directories" do
+      exclude = Configuration.from({})["exclude"]
+      assert_includes exclude, "vendor/bundle/"
+      assert_includes exclude, "vendor/cache/"
+      assert_includes exclude, "vendor/gems/"
+      assert_includes exclude, "vendor/ruby/"
+    end
   end
 
   context "#add_default_collections" do