diff --git a/Simulation/Overlay/OverlayConfiguration/CMakeLists.txt b/Simulation/Overlay/OverlayConfiguration/CMakeLists.txt
index a77429406ecfecb566604068aa4f1512a419c8d6..6c078af2f3c9100415f81e767d0ee50796035425 100644
--- a/Simulation/Overlay/OverlayConfiguration/CMakeLists.txt
+++ b/Simulation/Overlay/OverlayConfiguration/CMakeLists.txt
@@ -15,10 +15,10 @@ atlas_install_runtime( test/OverlayTest.py )
 # Setup and run tests
 atlas_add_test( OverlayTest_MC
                 SCRIPT test/OverlayTest.py
-                PROPERTIES TIMEOUT 600
+                PROPERTIES TIMEOUT 900
                 POST_EXEC_SCRIPT nopost.sh )
 
 atlas_add_test( OverlayTest_data
                 SCRIPT test/OverlayTest.py -d
-                PROPERTIES TIMEOUT 600
+                PROPERTIES TIMEOUT 900
                 POST_EXEC_SCRIPT nopost.sh )