diff --git a/src/playsim/a_dynlight.cpp b/src/playsim/a_dynlight.cpp
index 2bfcd393dd..4cd278b925 100644
--- a/src/playsim/a_dynlight.cpp
+++ b/src/playsim/a_dynlight.cpp
@@ -713,6 +713,7 @@ void FDynamicLight::UnlinkLight ()
 		}
 	}
 	delete touchlists;
+	touchlists = nullptr;
 	shadowmapped = false;
 }