diff --git a/extra/soundex/soundex-tests.factor b/extra/soundex/soundex-tests.factor
index df6338c4ec..f4bd18e34b 100644
--- a/extra/soundex/soundex-tests.factor
+++ b/extra/soundex/soundex-tests.factor
@@ -2,3 +2,4 @@ IN: soundex.tests
 USING: soundex tools.test ;
 
 [ "S162" ] [ "supercalifrag" soundex ] unit-test
+[ "M000" ] [ "M" soundex ] unit-test
diff --git a/extra/soundex/soundex.factor b/extra/soundex/soundex.factor
index c82825d814..23d5ee4d4c 100644
--- a/extra/soundex/soundex.factor
+++ b/extra/soundex/soundex.factor
@@ -25,8 +25,8 @@ TR: soundex-tr
         [ first>upper ]
         [
             soundex-tr
-            trim-first
-            remove-duplicates
+            [ "" ] [ trim-first ] if-empty
+            [ "" ] [ remove-duplicates ] if-empty
             remove-zeroes
         ] bi
         pad-4