diff --git a/source/games/duke/src/spawn.cpp b/source/games/duke/src/spawn.cpp
index bc2301f39..21e93b875 100644
--- a/source/games/duke/src/spawn.cpp
+++ b/source/games/duke/src/spawn.cpp
@@ -1101,8 +1101,8 @@ void spawneffector(DDukeActor* actor)
 			break;
 
 		case SE_29_WAVES:
-			//This does not work. Why?
-			//StartInterpolation(actor->s.sectnum, Interp_Sect_Floorheinum);
+			StartInterpolation(actor->s.sectnum, Interp_Sect_Floorheinum);
+			StartInterpolation(actor->s.sectnum, Interp_Sect_Floorz);
 			break;
 	}