diff --git a/landlock.cpp b/landlock.cpp
index db9a044a..690a635c 100644
--- a/landlock.cpp
+++ b/landlock.cpp
@@ -268,6 +268,7 @@ EX bool incompatible1(eLand l1, eLand l2) {
   if(l1 == laDeadCaves && l2 == laCaves) return true;
   if(l1 == laWarpSea && l2 == laKraken) return true;
   if(l1 == laPrairie && l2 == laCrossroads3) return true;
+  if(l1 == laPrairie && l2 == laCrossroads4) return true;
   if(l1 == laWet && l2 == laDesert) return true;
   if(l1 == laFrog && l2 == laMotion) return true;
   if(isElemental(l1) && isElemental(l2)) return true;