diff --git a/src/p_acs.cpp b/src/p_acs.cpp
index fa3c692b4..2377673b4 100644
--- a/src/p_acs.cpp
+++ b/src/p_acs.cpp
@@ -6825,7 +6825,7 @@ doplaysound:			if (funcIndex == ACSF_PlayActorSound)
 			int lineno = it.Next();
 			if (lineno < 0) return 0;
 			DVector2 delta = level.lines[lineno].Delta();
-			double result = delta[funcIndex - ACSF_GetLineX] * ACSToDouble(args[1]);
+			double result = level.lines[lineno].v1->fPos()[funcIndex - ACSF_GetLineX] + delta[funcIndex - ACSF_GetLineX] * ACSToDouble(args[1]);
 			if (args[2])
 			{
 				DVector2 normal = DVector2(delta.Y, -delta.X).Unit();