diff --git a/src/plugin/PluginManager.php b/src/plugin/PluginManager.php
index f996e58e4..4fff88cb0 100644
--- a/src/plugin/PluginManager.php
+++ b/src/plugin/PluginManager.php
@@ -471,8 +471,12 @@ class PluginManager{
 	}
 
 	public function tickSchedulers(int $currentTick) : void{
-		foreach($this->enabledPlugins as $p){
-			$p->getScheduler()->mainThreadHeartbeat($currentTick);
+		foreach($this->enabledPlugins as $pluginName => $p){
+			if(isset($this->enabledPlugins[$pluginName])){
+				//the plugin may have been disabled as a result of updating other plugins' schedulers, and therefore
+				//removed from enabledPlugins; however, foreach will still see it due to copy-on-write
+				$p->getScheduler()->mainThreadHeartbeat($currentTick);
+			}
 		}
 	}