diff --git a/mysql-test/t/count_distinct2.test b/mysql-test/t/count_distinct2.test
index 9100f622dec1d6b334a81ead1dfadd16445184a3..2b982e3e6207b6475594d31713b77f47d2ccd272 100644
--- a/mysql-test/t/count_distinct2.test
+++ b/mysql-test/t/count_distinct2.test
@@ -64,7 +64,7 @@ select count(distinct n) from t1;
 show status like 'Created_tmp_disk_tables';
 drop table t1;
 
-#test conversion from heap to MyISAM
+# Test use of MyISAM tmp tables
 create table t1 (s text);
 let $1=5000;
 disable_query_log;
diff --git a/sql/item_sum.cc b/sql/item_sum.cc
index b79edb9bebcf44155e66180b5fa04778a732a4b2..174e2ba4b85c6d3c2950a953c4693c23810ecb6e 100644
--- a/sql/item_sum.cc
+++ b/sql/item_sum.cc
@@ -2228,14 +2228,14 @@ bool Item_sum_count_distinct::setup(THD *thd)
     return FALSE;
 
   if (!(tmp_table_param= new TMP_TABLE_PARAM))
-    return 1;
+    return TRUE;
 
   /* Create a table with an unique key over all parameters */
   for (uint i=0; i < arg_count ; i++)
   {
     Item *item=args[i];
     if (list.push_back(item))
-      return 1;					// End of memory
+      return TRUE;                              // End of memory
     if (item->const_item())
     {
       (void) item->val_int();
@@ -2244,14 +2244,14 @@ bool Item_sum_count_distinct::setup(THD *thd)
     }
   }
   if (always_null)
-    return 0;
+    return FALSE;
   count_field_types(tmp_table_param,list,0);
   DBUG_ASSERT(table == 0);
   if (!(table= create_tmp_table(thd, tmp_table_param, list, (ORDER*) 0, 1,
 				0,
 				select_lex->options | thd->options,
 				HA_POS_ERROR, (char*)"")))
-    return 1;
+    return TRUE;
   table->file->extra(HA_EXTRA_NO_ROWS);		// Don't update rows
   table->no_rows=1;