diff --git a/icu4c/source/common/unicode/unistr.h b/icu4c/source/common/unicode/unistr.h
index cba1509a51d..8a03caac3ae 100644
--- a/icu4c/source/common/unicode/unistr.h
+++ b/icu4c/source/common/unicode/unistr.h
@@ -2753,7 +2753,7 @@ public:
   /** Destructor. 
    * @stable ICU 2.0
    */
-  ~UnicodeString();
+  virtual ~UnicodeString();
 
 
   /* Miscellaneous operations */