diff --git a/product/ERP5/tests/testSimulationPerformance.py b/product/ERP5/tests/testSimulationPerformance.py
index 4280c12886124d785def17a1a70ec6916d4c8148..82288659bcea6f69b86a3e27eef8e1557b60e92d 100644
--- a/product/ERP5/tests/testSimulationPerformance.py
+++ b/product/ERP5/tests/testSimulationPerformance.py
@@ -33,7 +33,8 @@ pystone.clock = time
 from Products.ERP5Type.tests.runUnitTest import ERP5TypeTestLoader
 from Products.ERP5.tests.testTradeModelLine import TestTradeModelLineSale
 
-ERP5TypeTestLoader._testMethodPrefix = 'perf'
+if ERP5TypeTestLoader._testMethodPrefix == 'test':
+  ERP5TypeTestLoader._testMethodPrefix = 'perf'
 
 class TestSimulationPerformance(TestTradeModelLineSale):