diff --git a/lib/fuzzily/trigram.rb b/lib/fuzzily/trigram.rb
index f8424c3..58821bf 100644
--- a/lib/fuzzily/trigram.rb
+++ b/lib/fuzzily/trigram.rb
@@ -21,7 +21,7 @@ def scored_trigrams
     def normalize
       ActiveSupport::Multibyte::Chars.new(self).
         mb_chars.normalize(:kd).gsub(/[^\x00-\x7F]/,'').downcase.to_s.
-        gsub(/[^a-z]/,' ').
+        gsub(/[^a-z\d]/,' ').
         gsub(/\s+/,'*').
         gsub(/^/,'**').
         gsub(/$/,'*')
diff --git a/spec/fuzzily/trigram_spec.rb b/spec/fuzzily/trigram_spec.rb
index 26bb0a1..16b6df7 100644
--- a/spec/fuzzily/trigram_spec.rb
+++ b/spec/fuzzily/trigram_spec.rb
@@ -5,7 +5,7 @@
   def result(string)
     described_class.new(string).trigrams
   end
-  
+
   it 'splits strings into trigrams' do
     result('Paris').should == %w(**p *pa par ari ris is*)
   end
@@ -22,4 +22,8 @@ def result(string)
     # The final ess, sse, se* would be dupes.
     result('Besse-en-Chandesse').should == %w(**b *be bes ess sse se* e*e *en en* n*c *ch cha han and nde des)
   end
+
+  it 'retain numbers' do
+    result('678 street').should == %w(**6 *67 678 78* 8*s *st str tre ree eet et*)
+  end
 end
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