diff --git a/mysql-test/r/union.result b/mysql-test/r/union.result
index 2a10f34d081..da89c7ce386 100644
--- a/mysql-test/r/union.result
+++ b/mysql-test/r/union.result
@@ -160,12 +160,12 @@ SELECT a FROM t1
 UNION
 SELECT a FROM t1
 ) alias;
-SELECT a INTO OUTFILE 'union.out.file' FROM (
+SELECT a INTO OUTFILE '<MYSQLTEST_VARDIR>/tmp/union.out.file' FROM (
 SELECT a FROM t1
 UNION
 SELECT a FROM t1 WHERE 0
 ) alias;
-SELECT a INTO DUMPFILE 'union.out.file2' FROM (
+SELECT a INTO DUMPFILE '<MYSQLTEST_VARDIR>/tmp/union.out.file' FROM (
 SELECT a FROM t1
 UNION
 SELECT a FROM t1 WHERE 0
@@ -178,21 +178,21 @@ SELECT a INTO @v FROM t1
 SELECT a FROM (
 SELECT a FROM t1
 UNION
-SELECT a INTO OUTFILE 'union.out.file3' FROM t1
+SELECT a INTO OUTFILE '<MYSQLTEST_VARDIR>/tmp/union.out.file' FROM t1
 ) alias;
 SELECT a FROM (
 SELECT a FROM t1
 UNION
-SELECT a INTO DUMPFILE 'union.out.file4' FROM t1
+SELECT a INTO DUMPFILE '<MYSQLTEST_VARDIR>/tmp/union.out.file' FROM t1
 ) alias;
 SELECT a FROM t1 UNION SELECT a INTO @v FROM t1;
-SELECT a FROM t1 UNION SELECT a INTO OUTFILE 'union.out.file5' FROM t1;
-SELECT a FROM t1 UNION SELECT a INTO OUTFILE 'union.out.file6' FROM t1;
+SELECT a FROM t1 UNION SELECT a INTO OUTFILE '<MYSQLTEST_VARDIR>/tmp/union.out.file' FROM t1;
+SELECT a FROM t1 UNION SELECT a INTO DUMPFILE '<MYSQLTEST_VARDIR>/tmp/union.out.file' FROM t1;
 SELECT a INTO @v FROM t1 UNION SELECT a FROM t1;
 ERROR HY000: Incorrect usage of UNION and INTO
-SELECT a INTO OUTFILE 'union.out.file7' FROM t1 UNION SELECT a FROM t1;
+SELECT a INTO OUTFILE '<MYSQLTEST_VARDIR>/tmp/union.out.file' FROM t1 UNION SELECT a FROM t1;
 ERROR HY000: Incorrect usage of UNION and INTO
-SELECT a INTO DUMPFILE 'union.out.file8' FROM t1 UNION SELECT a FROM t1;
+SELECT a INTO DUMPFILE '<MYSQLTEST_VARDIR>/tmp/union.out.file' FROM t1 UNION SELECT a FROM t1;
 ERROR HY000: Incorrect usage of UNION and INTO
 DROP TABLE t1;
 CREATE TABLE t1 (
diff --git a/mysql-test/t/union.test b/mysql-test/t/union.test
index ad4d57b7128..ee4c174d76b 100644
--- a/mysql-test/t/union.test
+++ b/mysql-test/t/union.test
@@ -105,17 +105,25 @@ SELECT a INTO @v FROM (
   SELECT a FROM t1
 ) alias;
 
-SELECT a INTO OUTFILE 'union.out.file' FROM (
-  SELECT a FROM t1
-  UNION
-  SELECT a FROM t1 WHERE 0
-) alias;
+--let $outfile = $MYSQLTEST_VARDIR/tmp/union.out.file
+--error 0,1
+--remove_file $outfile
 
-SELECT a INTO DUMPFILE 'union.out.file2' FROM (
+--replace_result $MYSQLTEST_VARDIR <MYSQLTEST_VARDIR>
+eval SELECT a INTO OUTFILE '$outfile' FROM (
   SELECT a FROM t1
   UNION
   SELECT a FROM t1 WHERE 0
 ) alias;
+--remove_file $outfile
+
+--replace_result $MYSQLTEST_VARDIR <MYSQLTEST_VARDIR>
+eval SELECT a INTO DUMPFILE '$outfile' FROM (
+  SELECT a FROM t1
+  UNION
+  SELECT a FROM t1 WHERE 0
+) alias;
+--remove_file $outfile
 
 #
 # INTO will not be allowed in subqueries in version 5.1 and above.
@@ -126,27 +134,42 @@ SELECT a FROM (
   SELECT a INTO @v FROM t1
 ) alias;
 
-SELECT a FROM (
+--replace_result $MYSQLTEST_VARDIR <MYSQLTEST_VARDIR>
+eval SELECT a FROM (
   SELECT a FROM t1
   UNION
-  SELECT a INTO OUTFILE 'union.out.file3' FROM t1
+  SELECT a INTO OUTFILE '$outfile' FROM t1
 ) alias;
+--remove_file $outfile
 
-SELECT a FROM (
+--replace_result $MYSQLTEST_VARDIR <MYSQLTEST_VARDIR>
+eval SELECT a FROM (
   SELECT a FROM t1
   UNION
-  SELECT a INTO DUMPFILE 'union.out.file4' FROM t1
+  SELECT a INTO DUMPFILE '$outfile' FROM t1
 ) alias;
+--remove_file $outfile
 
 SELECT a FROM t1 UNION SELECT a INTO @v FROM t1;
-SELECT a FROM t1 UNION SELECT a INTO OUTFILE 'union.out.file5' FROM t1;
-SELECT a FROM t1 UNION SELECT a INTO OUTFILE 'union.out.file6' FROM t1;
+
+--replace_result $MYSQLTEST_VARDIR <MYSQLTEST_VARDIR>
+eval SELECT a FROM t1 UNION SELECT a INTO OUTFILE '$outfile' FROM t1;
+--remove_file $outfile
+
+--replace_result $MYSQLTEST_VARDIR <MYSQLTEST_VARDIR>
+eval SELECT a FROM t1 UNION SELECT a INTO DUMPFILE '$outfile' FROM t1;
+--remove_file $outfile
+
 --error ER_WRONG_USAGE
 SELECT a INTO @v FROM t1 UNION SELECT a FROM t1;
+
+--replace_result $MYSQLTEST_VARDIR <MYSQLTEST_VARDIR>
 --error ER_WRONG_USAGE
-SELECT a INTO OUTFILE 'union.out.file7' FROM t1 UNION SELECT a FROM t1;
+eval SELECT a INTO OUTFILE '$outfile' FROM t1 UNION SELECT a FROM t1;
+
+--replace_result $MYSQLTEST_VARDIR <MYSQLTEST_VARDIR>
 --error ER_WRONG_USAGE
-SELECT a INTO DUMPFILE 'union.out.file8' FROM t1 UNION SELECT a FROM t1;
+eval SELECT a INTO DUMPFILE '$outfile' FROM t1 UNION SELECT a FROM t1;
 
 DROP TABLE t1;