diff --git a/tests/visual_tests/styles/collision.xml b/tests/visual_tests/styles/collision.xml
index 3bd807de0..7b717fc9f 100644
--- a/tests/visual_tests/styles/collision.xml
+++ b/tests/visual_tests/styles/collision.xml
@@ -9,6 +9,7 @@
   <Style name="text">
     <Rule>
       <TextSymbolizer spacing="10" size="14" halo-radius="2" face-name="DejaVu Sans Oblique" placement="line">'text'</TextSymbolizer>
+      <DebugSymbolizer />
     </Rule>
   </Style>