diff --git a/server/src/io/anuke/mindustry/server/ServerControl.java b/server/src/io/anuke/mindustry/server/ServerControl.java
index 7cff7e1711..73f2ad89e4 100644
--- a/server/src/io/anuke/mindustry/server/ServerControl.java
+++ b/server/src/io/anuke/mindustry/server/ServerControl.java
@@ -74,6 +74,11 @@ public class ServerControl extends Module{
         thread.setDaemon(true);
         thread.start();
 
+        if(Version.build == -1){
+            err("WARNING: &lyYour server is running a custom build, which means that client checking is disabled.\n" +
+            "&lrWARNING: &lyIt is highly advised to specify which version you're using by building with gradle args &lc-Pbuildversion=&lm<build>&ly so that clients know which version you are using.");
+        }
+
         Events.on(GameOverEvent.class, () -> {
             info("Game over!");