diff --git a/src/my_pool_chunk.h b/src/my_pool_chunk.h
index 502f7e36ef..a4d45306cc 100644
--- a/src/my_pool_chunk.h
+++ b/src/my_pool_chunk.h
@@ -89,6 +89,7 @@ class MyPoolChunk {
 
     ndatum = nchunk = size = 0;
     pages = NULL;
+    whichbin = NULL;
     npage = 0;
   }