diff --git a/src/decallib.cpp b/src/decallib.cpp
index d20adc921a..bfcc1ac147 100644
--- a/src/decallib.cpp
+++ b/src/decallib.cpp
@@ -403,7 +403,7 @@ void FDecalLib::ReadDecals(FScanner &sc)
 		}
 		else
 		{
-			sc.MustGetStringName(NULL);
+			sc.ScriptError("Unknown decaldef keyword '%s'", sc.String);
 		}
 	}
 }