diff --git a/src/p_acs.cpp b/src/p_acs.cpp
index 5f08f01526..a2b5275cbe 100644
--- a/src/p_acs.cpp
+++ b/src/p_acs.cpp
@@ -4449,6 +4449,8 @@ enum EACSFunctions
 	-106 : KickFromGame(2),
 	*/
 
+	ACSF_CheckClass = 200,
+
 	// ZDaemon
 	ACSF_GetTeamScore = 19620,	// (int team)
 	ACSF_SetTeamScore,			// (int team, int value)
@@ -6028,6 +6030,12 @@ doplaysound:			if (funcIndex == ACSF_PlayActorSound)
 			return false;
 		}
 
+		case ACSF_CheckClass:
+		{
+			const char *clsname = FBehavior::StaticLookupString(args[0]);
+			return !!PClass::FindActor(clsname);
+		}
+
 		default:
 			break;
 	}