diff --git a/db/boinc_db.cpp b/db/boinc_db.cpp
index 86544e72b201b727ad31a78f43b3d1acd3e00a21..65a7ed395bd17d79329aa4727cacdf819f2fc533 100644
--- a/db/boinc_db.cpp
+++ b/db/boinc_db.cpp
@@ -55,8 +55,8 @@ void APP_VERSION::clear() {memset(this, 0, sizeof(*this));}
 void USER::clear() {memset(this, 0, sizeof(*this));}
 void TEAM::clear() {memset(this, 0, sizeof(*this));}
 void HOST::clear() {memset(this, 0, sizeof(*this));}
-void RESULT::clear() {memset(this, 0, sizeof(*this));}
-void WORKUNIT::clear() {memset(this, 0, sizeof(*this));}
+void RESULT::clear() {memset(this, 0, sizeof(*this)); size_class=-1;}
+void WORKUNIT::clear() {memset(this, 0, sizeof(*this)); size_class=-1;}
 void CREDITED_JOB::clear() {memset(this, 0, sizeof(*this));}
 void MSG_FROM_HOST::clear() {memset(this, 0, sizeof(*this));}
 void MSG_TO_HOST::clear() {memset(this, 0, sizeof(*this));}