Index: src/sqliteInt.h
==================================================================
--- src/sqliteInt.h
+++ src/sqliteInt.h
@@ -3178,10 +3178,11 @@
 **    OPFLAG_SAVEPOSITION == BTREE_SAVEPOSITION
 **    OPFLAG_AUXDELETE    == BTREE_AUXDELETE
 */
 #define OPFLAG_NCHANGE       0x01    /* OP_Insert: Set to update db->nChange */
                                      /* Also used in P2 (not P5) of OP_Delete */
+#define OPFLAG_NOCHNG        0x01    /* OP_VColumn nochange for UPDATE */
 #define OPFLAG_EPHEM         0x01    /* OP_Column: Ephemeral output is ok */
 #define OPFLAG_LASTROWID     0x20    /* Set to update db->lastRowid */
 #define OPFLAG_ISUPDATE      0x04    /* This OP_Insert is an sql UPDATE */
 #define OPFLAG_APPEND        0x08    /* This is likely to be an append */
 #define OPFLAG_USESEEKRESULT 0x10    /* Try to avoid a seek in BtreeInsert() */

Index: src/update.c
==================================================================
--- src/update.c
+++ src/update.c
@@ -911,11 +911,11 @@
   for(i=0; i<pTab->nCol; i++){
     if( aXRef[i]>=0 ){
       sqlite3ExprCode(pParse, pChanges->a[aXRef[i]].pExpr, regArg+2+i);
     }else{
       sqlite3VdbeAddOp3(v, OP_VColumn, iCsr, i, regArg+2+i);
-      sqlite3VdbeChangeP5(v, 1); /* Enable sqlite3_vtab_nochange() */
+      sqlite3VdbeChangeP5(v, OPFLAG_NOCHNG);/* Enable sqlite3_vtab_nochange() */
     }
   }
   if( HasRowid(pTab) ){
     sqlite3VdbeAddOp2(v, OP_Rowid, iCsr, regArg);
     if( pRowid ){

Index: src/vdbe.c
==================================================================
--- src/vdbe.c
+++ src/vdbe.c
@@ -6963,14 +6963,15 @@
 ** Store in register P3 the value of the P2-th column of
 ** the current row of the virtual-table of cursor P1.
 **
 ** If the VColumn opcode is being used to fetch the value of
 ** an unchanging column during an UPDATE operation, then the P5
-** value is 1.  Otherwise, P5 is 0.  The P5 value is returned
-** by sqlite3_vtab_nochange() routine and can be used
-** by virtual table implementations to return special "no-change"
-** marks which can be more efficient, depending on the virtual table.
+** value is OPFLAG_NOCHNG.  This will cause the sqlite3_vtab_nochange()
+** function to return true inside the xColumn method of the virtual
+** table implementation.  The P5 column might also contain other
+** bits (OPFLAG_LENGTHARG or OPFLAG_TYPEOFARG) but those bits are
+** unused by OP_VColumn.
 */
 case OP_VColumn: {
   sqlite3_vtab *pVtab;
   const sqlite3_module *pModule;
   Mem *pDest;
@@ -6988,11 +6989,12 @@
   pVtab = pCur->uc.pVCur->pVtab;
   pModule = pVtab->pModule;
   assert( pModule->xColumn );
   memset(&sContext, 0, sizeof(sContext));
   sContext.pOut = pDest;
-  if( pOp->p5 ){
+  testcase( (pOp->p5 & OPFLAG_NOCHNG)==0 && pOp->p5!=0 );
+  if( pOp->p5 & OPFLAG_NOCHNG ){
     sqlite3VdbeMemSetNull(pDest);
     pDest->flags = MEM_Null|MEM_Zero;
     pDest->u.nZero = 0;
   }else{
     MemSetTypeFlag(pDest, MEM_Null);