diff --git a/core/src/mindustry/ai/RtsAI.java b/core/src/mindustry/ai/RtsAI.java
index 8660cbb10b..1d0befd241 100644
--- a/core/src/mindustry/ai/RtsAI.java
+++ b/core/src/mindustry/ai/RtsAI.java
@@ -174,7 +174,7 @@ public class RtsAI{
 
             //defend when close, or this is the only squad defending
             //TODO will always rush to defense no matter what
-            if(best instanceof CoreBuild || units.size >= data.team.rules().rtsMinSquad || best.within(ax, ay, 500f)){
+            if(best != null && (best instanceof CoreBuild || units.size >= data.team.rules().rtsMinSquad || best.within(ax, ay, 500f))){
                 defend = best;
 
                 if(debug){