1 files changed, 1 insertions, 0 deletions
diff --git a/src/btree.c b/src/btree.c
index e98cb7b05..d0be54990 100644
--- a/src/btree.c
+++ b/src/btree.c
@@ -7989,6 +7989,7 @@ static int balance_nonroot(
       while( i==cntOldNext ){
         iOld++;
         assert( iOld<nNew || iOld<nOld );
+        assert( iOld>=0 && iOld<NB );
         pOld = iOld<nNew ? apNew[iOld] : apOld[iOld];
         cntOldNext += pOld->nCell + pOld->nOverflow + !leafData;
       }