1 files changed, 1 insertions, 0 deletions
diff --git a/src/vdbeapi.c b/src/vdbeapi.c
index 5eeb5d1c0..17df807de 100644
--- a/src/vdbeapi.c
+++ b/src/vdbeapi.c
@@ -1850,6 +1850,7 @@ int sqlite3_preupdate_old(sqlite3 *db, int iIdx, sqlite3_value **ppValue){
     u32 nRec;
     u8 *aRec;
 
+    assert( p->pCsr->eCurType==CURTYPE_BTREE );
     nRec = sqlite3BtreePayloadSize(p->pCsr->uc.pCursor);
     aRec = sqlite3DbMallocRaw(db, nRec);
     if( !aRec ) goto preupdate_old_out;