1 files changed, 5 insertions, 0 deletions
diff --git a/src/whereexpr.c b/src/whereexpr.c
index 09ed7f6c3..f547db4f0 100644
--- a/src/whereexpr.c
+++ b/src/whereexpr.c
@@ -1407,6 +1407,11 @@ static void exprAnalyze(
       pNew->prereqRight = prereqLeft | extraRight;
       pNew->prereqAll = prereqAll;
       pNew->eOperator = (operatorMask(pDup->op) + eExtraOp) & opMask;
+    }else if( op==TK_ISNULL && 0==sqlite3ExprCanBeNull(pLeft) ){
+      pExpr->op = TK_TRUEFALSE;
+      ExprSetProperty(pExpr, EP_IsFalse);
+      pTerm->prereqAll = 0;
+      pTerm->eOperator = 0;
     }
   }