diff --git a/xpcom/tests/TestBase64.cpp b/xpcom/tests/TestBase64.cpp
index 70b1d8f375d..0b7cba160d1 100644
--- a/xpcom/tests/TestBase64.cpp
+++ b/xpcom/tests/TestBase64.cpp
@@ -145,6 +145,8 @@ static Test kTests[] =
 
 class FakeInputStream MOZ_FINAL : public nsIInputStream
 {
+  ~FakeInputStream() {}
+
 public:
 
   FakeInputStream()