diff --git a/src/p_acs.cpp b/src/p_acs.cpp
index 4a2ca3fd9b..baf15c1105 100644
--- a/src/p_acs.cpp
+++ b/src/p_acs.cpp
@@ -4368,6 +4368,9 @@ enum EACSFunctions
 	ACSF_GetActorFloorTexture,
 	ACSF_GetActorFloorTerrain,
 	ACSF_StrArg,
+	ACSF_Floor,
+	ACSF_Ceil,
+	ACSF_Round,
 
 
 	// OpenGL stuff
@@ -6091,6 +6094,15 @@ doplaysound:			if (funcIndex == ACSF_PlayActorSound)
 		case ACSF_StrArg:
 			return -FName(FBehavior::StaticLookupString(args[0]));
 
+		case ACSF_Floor:
+			return args[0] & ~0xffff;
+
+		case ACSF_Ceil:
+			return (args[0] & ~0xffff) + 0x10000;
+
+		case ACSF_Round:
+			return (args[0] + 32768) & ~0xffff;
+
 		default:
 			break;
 	}