diff --git a/libmysql/libmysql.c b/libmysql/libmysql.c
index 783082c6b03..977657f8998 100644
--- a/libmysql/libmysql.c
+++ b/libmysql/libmysql.c
@@ -2035,14 +2035,6 @@ int cli_stmt_execute(MYSQL_STMT *stmt)
     uint null_count;
     my_bool    result;
 
-#ifdef CHECK_EXTRA_ARGUMENTS
-    if (!stmt->param_buffers)
-    {
-      /* Parameters exists, but no bound buffers */
-      set_stmt_error(stmt, CR_NOT_ALL_PARAMS_BOUND, unknown_sqlstate);
-      DBUG_RETURN(1);
-    }
-#endif
     net_clear(net);				/* Sets net->write_pos */
     /* Reserve place for null-marker bytes */
     null_count= (stmt->param_count+7) /8;
@@ -2099,6 +2091,14 @@ int STDCALL mysql_execute(MYSQL_STMT *stmt)
     set_stmt_error(stmt, CR_NO_PREPARE_STMT, unknown_sqlstate);
     DBUG_RETURN(1);
   }
+#ifdef CHECK_EXTRA_ARGUMENTS
+  if (stmt->param_count && !stmt->param_buffers)
+  {
+    /* Parameters exists, but no bound buffers */
+    set_stmt_error(stmt, CR_NOT_ALL_PARAMS_BOUND, unknown_sqlstate);
+    DBUG_RETURN(1);
+  }
+#endif
   if ((*stmt->mysql->methods->stmt_execute)(stmt))
     DBUG_RETURN(1);
       
diff --git a/sql/sql_class.cc b/sql/sql_class.cc
index 12f0cc4ca72..60220ffc889 100644
--- a/sql/sql_class.cc
+++ b/sql/sql_class.cc
@@ -336,6 +336,8 @@ THD::~THD()
 #ifndef DBUG_OFF
   dbug_sentry = THD_SENTRY_GONE;
 #endif  
+  /* Reset stmt_backup.mem_root to not double-free memory from thd.mem_root */
+  init_alloc_root(&stmt_backup.mem_root, 0, 0);
   DBUG_VOID_RETURN;
 }
 
diff --git a/sql/sql_class.h b/sql/sql_class.h
index c1cd65edf76..5390e8a4ac4 100644
--- a/sql/sql_class.h
+++ b/sql/sql_class.h
@@ -582,8 +582,7 @@ public:
   Statement_map stmt_map; 
   /*
     keeps THD state while it is used for active statement
-    Note, that double free_root() is safe, so we don't need to do any
-    special cleanup for it in THD destructor.
+    Note: we perform special cleanup for it in THD destructor.
   */
   Statement stmt_backup;
   /*
diff --git a/sql/sql_prepare.cc b/sql/sql_prepare.cc
index a513e445db9..5d6ab165641 100644
--- a/sql/sql_prepare.cc
+++ b/sql/sql_prepare.cc
@@ -1193,7 +1193,7 @@ Prepared_statement::Prepared_statement(THD *thd_arg)
 #ifndef EMBEDDED_LIBRARY
     setup_params= insert_params; // not fully qualified query
 #else
-    setup_params_data= setup_params_data;
+    setup_params_data= ::setup_params_data;
 #endif
 }