diff --git a/src/uncategorized/BackwardsCompatibility.tw b/src/uncategorized/BackwardsCompatibility.tw
index f84ed53cbf709749c153c09be0ab1d3c64d463b1..6ae31f0bb45fc0f83829e937ab90b0e95729dd47 100644
--- a/src/uncategorized/BackwardsCompatibility.tw
+++ b/src/uncategorized/BackwardsCompatibility.tw
@@ -2200,6 +2200,10 @@ Setting missing global variables:
 	<</if>>
 <</for>>
 
+<<if ndef $PC.ID>>
+	<<set $PC.ID = -1>>
+<</if>>
+
 <<if !($ver.startsWith("0.10"))>>
 	<<if $PC.refreshment == "cigar">>
 		<<set $PC.refreshmentType = 0>>