diff --git a/src/kits/support/String.cpp b/src/kits/support/String.cpp
index a38c46c2fe..fcf56cbd1f 100644
--- a/src/kits/support/String.cpp
+++ b/src/kits/support/String.cpp
@@ -1797,7 +1797,7 @@ BString::_IsShareable()
 void
 BString::_FreePrivateData()
 {
-	free(fPrivateData - (2 * sizeof(int32)));
+	free(fPrivateData - kPrivateDataOffset);
 }