diff --git a/lib/prawn/font/afm.rb b/lib/prawn/font/afm.rb
index 04c510e04..1ffc3fe60 100644
--- a/lib/prawn/font/afm.rb
+++ b/lib/prawn/font/afm.rb
@@ -49,8 +49,10 @@ def self.font_data
       end
 
       def initialize(document, name, options = {}) #:nodoc:
+        name ||= options[:family]
         unless BUILT_INS.include?(name)
-          raise Prawn::Errors::UnknownFont, "#{name} is not a known font."
+          raise Prawn::Errors::UnknownFont,
+            "#{name} (#{options[:style] || 'normal'}) is not a known font."
         end
 
         super
diff --git a/spec/prawn/font_spec.rb b/spec/prawn/font_spec.rb
index 922479f4f..ca1ae2872 100644
--- a/spec/prawn/font_spec.rb
+++ b/spec/prawn/font_spec.rb
@@ -69,6 +69,14 @@
       end
     end
 
+    it 'reports missing font with style' do
+      expect do
+        pdf.font('Nada', style: :bold) do
+          pdf.width_of('hello')
+        end
+      end.to raise_error(Prawn::Errors::UnknownFont, /Nada \(bold\)/)
+    end
+
     it 'calculates styled widths correctly using TTFs' do
       pdf.font_families.update(
         'DejaVu Sans' => {