diff --git a/include/boost/unordered/detail/foa/core.hpp b/include/boost/unordered/detail/foa/core.hpp
index f7fdc899..59d1084b 100644
--- a/include/boost/unordered/detail/foa/core.hpp
+++ b/include/boost/unordered/detail/foa/core.hpp
@@ -910,11 +910,14 @@ struct table_arrays
           reinterpret_cast<uintptr_t>(p))%sizeof(group_type);
       arrays.groups=reinterpret_cast<group_type*>(p);
 
+      for (std::size_t i=0;i<groups_size;++i){
+        new(arrays.groups+i) group_type();
+      }
+
       /* memset is faster/not slower than initializing groups individually.
        * This assumes all zeros is group_type's default layout. 
        */
-
-      std::memset(arrays.groups,0,sizeof(group_type)*groups_size);
+      // std::memset(arrays.groups,0,sizeof(group_type)*groups_size);
       arrays.groups[groups_size-1].set_sentinel();
     }
     return arrays;