diff --git a/implementations/spigot/src/main/java/de/bluecolored/bluemap/bukkit/BukkitCommands.java b/implementations/spigot/src/main/java/de/bluecolored/bluemap/bukkit/BukkitCommands.java
index 0125dbf8..fb27495a 100644
--- a/implementations/spigot/src/main/java/de/bluecolored/bluemap/bukkit/BukkitCommands.java
+++ b/implementations/spigot/src/main/java/de/bluecolored/bluemap/bukkit/BukkitCommands.java
@@ -32,6 +32,7 @@
 import java.util.concurrent.TimeoutException;
 
 import org.apache.commons.lang.StringUtils;
+import org.bukkit.Bukkit;
 import org.bukkit.ChatColor;
 import org.bukkit.command.CommandSender;
 import org.bukkit.command.defaults.BukkitCommand;
@@ -88,8 +89,16 @@ public void onTabComplete(TabCompleteEvent evt) {
 			}
 			
 			if (!completions.isEmpty()) {
-				completions.sort((s1, s2) -> s1.compareToIgnoreCase(s2));
-				evt.getCompletions().addAll(completions);
+				completions.sort(String::compareToIgnoreCase);
+
+				try {
+					evt.getCompletions().addAll(completions);
+				} catch (UnsupportedOperationException ex){
+					// fix for a bug with paper where the completion-Collection is not mutable for some reason
+					List<String> mutableCompletions = new ArrayList<>(evt.getCompletions());
+					mutableCompletions.addAll(completions);
+					evt.setCompletions(mutableCompletions);
+				}
 			}
 		} catch (InterruptedException ignore) {
 			Thread.currentThread().interrupt();