diff --git a/app/lib/world/script_event_prereqs.coffee b/app/lib/world/script_event_prereqs.coffee
index d9a455eb1..128a8f6bd 100644
--- a/app/lib/world/script_event_prereqs.coffee
+++ b/app/lib/world/script_event_prereqs.coffee
@@ -11,7 +11,7 @@ module.exports.scriptMatchesEventPrereqs = scriptMatchesEventPrereqs = (script,
     return false if ap.lessThan? and not (v < ap.lessThan)
     return false if ap.lessThanOrEqualTo? and not (v <= ap.lessThanOrEqualTo)
     return false if ap.containingString? and (not v or v.search(ap.containingString) is -1)
-    return false if ap.notContainingString? and v?.search(ap.containingString) isnt -1
+    return false if ap.notContainingString? and v?.search(ap.notContainingString) isnt -1
     return false if ap.containingRegexp? and (not v or v.search(new RegExp(ap.containingRegexp)) is -1)
     return false if ap.notContainingRegexp? and v?.search(new RegExp(ap.notContainingRegexp)) isnt -1