diff --git a/src/main/java/me/clip/placeholderapi/expansion/manager/LocalExpansionManager.java b/src/main/java/me/clip/placeholderapi/expansion/manager/LocalExpansionManager.java
index 8b55e26..3286071 100644
--- a/src/main/java/me/clip/placeholderapi/expansion/manager/LocalExpansionManager.java
+++ b/src/main/java/me/clip/placeholderapi/expansion/manager/LocalExpansionManager.java
@@ -286,7 +286,7 @@ public final class LocalExpansionManager implements Listener {
 
   @ApiStatus.Internal
   public boolean unregister(@NotNull final PlaceholderExpansion expansion) {
-    if (expansions.remove(expansion.getIdentifier()) == null) {
+    if (expansions.remove(expansion.getIdentifier().toLowerCase(Locale.ROOT)) == null) {
       return false;
     }