Index: ext/rtree/rtree.c
==================================================================
--- ext/rtree/rtree.c
+++ ext/rtree/rtree.c
@@ -623,12 +623,13 @@
 /*
 ** Clear the Rtree.pNodeBlob object
 */
 static void nodeBlobReset(Rtree *pRtree){
   if( pRtree->pNodeBlob && pRtree->inWrTrans==0 && pRtree->nCursor==0 ){
-    sqlite3_blob_close(pRtree->pNodeBlob);
+    sqlite3_blob *pBlob = pRtree->pNodeBlob;
     pRtree->pNodeBlob = 0;
+    sqlite3_blob_close(pBlob);
   }
 }
 
 /*
 ** Obtain a reference to an r-tree node.