diff --git a/CHANGELOG.md b/CHANGELOG.md
index f42a793..9551573 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,7 @@ Squib follows [semantic versioning](http://semver.org).
 
 Chores:
 * Ripped out a lot of old constants used from the old way we handled arguments. Yay negative churn!
+* Emit a warning when a `config.yml` option is not recognized
 
 ## v0.8.0 / 2015-10-26
 Features
diff --git a/lib/squib/conf.rb b/lib/squib/conf.rb
index 954cd22..ce3f395 100644
--- a/lib/squib/conf.rb
+++ b/lib/squib/conf.rb
@@ -52,6 +52,7 @@ module Squib
         Squib::logger.info { "  using config: #{file}" }
         yaml = YAML.load_file(file) || {}
       end
+      warn_unrecognized(yaml)
       Conf.new(DEFAULTS.merge(yaml))
     end
 
@@ -113,5 +114,13 @@ module Squib
       @config_hash['antialias'] = ANTIALIAS_OPTS[@config_hash['antialias'].downcase.strip]
     end
 
+    # Were there any unrecognized options in the config file?
+    def self.warn_unrecognized(yaml)
+      unrec = yaml.keys - DEFAULTS.keys
+      if unrec.any?
+        Squib::logger.warn "Unrecognized configuration option(s): #{unrec.join(',')}"
+      end
+    end
+
   end
 end
diff --git a/spec/conf_spec.rb b/spec/conf_spec.rb
index 82a798d..c7c619f 100644
--- a/spec/conf_spec.rb
+++ b/spec/conf_spec.rb
@@ -4,17 +4,17 @@ require 'spec_helper'
 describe Squib::Conf do
 
   it 'parses the project template file just fine' do
-    conf = Squib::Conf.load(project_template('config.yml'))
+    conf = Squib::Conf.load project_template('config.yml')
     expect(conf.backend).to eq(Squib::Conf::DEFAULTS['backend'])
   end
 
   it 'parses an empty file' do
-    conf = Squib::Conf.load(conf('empty.yml'))
+    conf = Squib::Conf.load conf('empty.yml')
     expect(conf.backend).to eq(Squib::Conf::DEFAULTS['backend'])
   end
 
   it 'parses the sample custom config' do
-    conf = Squib::Conf.load(sample_file('custom-config.yml'))
+    conf = Squib::Conf.load sample_file('custom-config.yml')
     expect(conf.progress_bars).to  be true
     expect(conf.text_hint).to      eq '#FF0000'
     expect(conf.custom_colors).to  eq({ 'foo' => '#ccc' })
@@ -26,4 +26,9 @@ describe Squib::Conf do
     expect(Squib::Conf.new.antialias).to          eq 'subpixel'
   end
 
+  it 'warns when the yml has an unrecognized option' do
+    expect(Squib::logger).to receive(:warn).with('Unrecognized configuration option(s): unicorns')
+    Squib::Conf.load conf('unrecognized.yml')
+  end
+
 end
diff --git a/spec/data/conf/unrecognized.yml b/spec/data/conf/unrecognized.yml
new file mode 100644
index 0000000..fc2253b
--- /dev/null
+++ b/spec/data/conf/unrecognized.yml
@@ -0,0 +1,4 @@
+# This is recognized, so it should be fine.
+backend: svg
+# This is not recognized.
+unicorns: true
\ No newline at end of file