diff --git a/Tests/RunCMake/ctest_test/RunCMakeTest.cmake b/Tests/RunCMake/ctest_test/RunCMakeTest.cmake
index e2f380c3a..1b3172676 100644
--- a/Tests/RunCMake/ctest_test/RunCMakeTest.cmake
+++ b/Tests/RunCMake/ctest_test/RunCMakeTest.cmake
@@ -71,6 +71,7 @@ add_test(NAME PassingTest COMMAND ${CMAKE_COMMAND} -E echo PassingTestOutput)
 add_test(NAME FailingTest COMMAND ${CMAKE_COMMAND} -E no_such_command)
   ]])
 
+  unset(ENV{CTEST_PARALLEL_LEVEL})
   run_ctest(TestOutputSize)
 endfunction()
 run_TestOutputSize()
diff --git a/Tests/RunCMake/ctest_test/TestOutputSize-check.cmake b/Tests/RunCMake/ctest_test/TestOutputSize-check.cmake
index 918d242aa..74ad6695b 100644
--- a/Tests/RunCMake/ctest_test/TestOutputSize-check.cmake
+++ b/Tests/RunCMake/ctest_test/TestOutputSize-check.cmake
@@ -4,14 +4,14 @@ if(test_xml_file)
   if("${test_xml}" MATCHES [[(<Test Status="passed">.*</Test>).*(<Test Status="failed">.*</Test>)]])
     set(test_passed "${CMAKE_MATCH_1}")
     set(test_failed "${CMAKE_MATCH_2}")
+    if(NOT "${test_passed}" MATCHES [[<Value>PassingTes\.\.\..*10 bytes]])
+      set(RunCMake_TEST_FAILED "Test.xml passed test output not truncated at 10 bytes:\n ${test_passed}")
+    elseif(NOT "${test_failed}" MATCHES [[<Value>CMake Error:\.\.\..*12 bytes]])
+      set(RunCMake_TEST_FAILED "Test.xml failed test output not truncated at 12 bytes:\n ${test_failed}")
+    endif()
   else()
     set(RunCMake_TEST_FAILED "Test.xml does not contain a passed then failed test:\n ${test_xml}")
   endif()
-  if(NOT "${test_passed}" MATCHES [[<Value>PassingTes\.\.\..*10 bytes]])
-    set(RunCMake_TEST_FAILED "Test.xml passed test output not truncated at 10 bytes:\n ${test_passed}")
-  elseif(NOT "${test_failed}" MATCHES [[<Value>CMake Error:\.\.\..*12 bytes]])
-    set(RunCMake_TEST_FAILED "Test.xml failed test output not truncated at 12 bytes:\n ${test_failed}")
-  endif()
 else()
   set(RunCMake_TEST_FAILED "Test.xml not found")
 endif()