diff --git a/pluralize.js b/pluralize.js
index 1829fc8..48d4cb3 100644
--- a/pluralize.js
+++ b/pluralize.js
@@ -336,7 +336,7 @@
     [/(alias|[^aou]us|t[lm]as|gas|ris)$/i, '$1es'],
     [/(e[mn]u)s?$/i, '$1s'],
     [/([^l]ias|[aeiou]las|[ejzr]as|[iu]am)$/i, '$1'],
-    [/(alumn|syllab|vir|radi|nucle|fung|cact|stimul|termin|bacill|foc|uter|loc|strat)(?:us|i)$/i, '$1i'],
+    [/(alumn|syllab|vir|radi|nucle|fung|cact|stimul|termin|bacill|foc|uter|loc|strat|pri)(?:us|i)$/i, '$1i'],
     [/(alumn|alg|vertebr)(?:a|ae)$/i, '$1ae'],
     [/(seraph|cherub)(?:im)?$/i, '$1im'],
     [/(her|at|gr)o$/i, '$1oes'],
@@ -376,7 +376,7 @@
     [/(analy|diagno|parenthe|progno|synop|the|empha|cri|ne)(?:sis|ses)$/i, '$1sis'],
     [/(movie|twelve|abuse|e[mn]u)s$/i, '$1'],
     [/(test)(?:is|es)$/i, '$1is'],
-    [/(alumn|syllab|vir|radi|nucle|fung|cact|stimul|termin|bacill|foc|uter|loc|strat)(?:us|i)$/i, '$1us'],
+    [/(alumn|syllab|vir|radi|nucle|fung|cact|stimul|termin|bacill|foc|uter|loc|strat|pri)(?:us|i)$/i, '$1us'],
     [/(agend|addend|millenni|dat|extrem|bacteri|desiderat|strat|candelabr|errat|ov|symposi|curricul|quor)a$/i, '$1um'],
     [/(apheli|hyperbat|periheli|asyndet|noumen|phenomen|criteri|organ|prolegomen|hedr|automat)a$/i, '$1on'],
     [/(alumn|alg|vertebr)ae$/i, '$1a'],
diff --git a/test.js b/test.js
index fc84d37..defa1a5 100644
--- a/test.js
+++ b/test.js
@@ -534,6 +534,7 @@ var BASIC_TESTS = [
   ['radius', 'radii'],
   ['stratum', 'strata'],
   ['stratus', 'strati'],
+  ['prius', 'prii'],
   ['focus', 'foci'],
   ['fungus', 'fungi'],
   ['appendix', 'appendices'],