diff --git a/eco-core/core-plugin/src/main/kotlin/com/willfp/eco/internal/spigot/data/EcoKeyRegistry.kt b/eco-core/core-plugin/src/main/kotlin/com/willfp/eco/internal/spigot/data/EcoKeyRegistry.kt
index 3e5e4fd8..23dddb14 100644
--- a/eco-core/core-plugin/src/main/kotlin/com/willfp/eco/internal/spigot/data/EcoKeyRegistry.kt
+++ b/eco-core/core-plugin/src/main/kotlin/com/willfp/eco/internal/spigot/data/EcoKeyRegistry.kt
@@ -29,19 +29,24 @@ class EcoKeyRegistry : KeyRegistry {
     }
 
     private fun <T> validateKey(key: PersistentDataKey<T>) {
+        val default = key.defaultValue
+
         when (key.type) {
-            PersistentDataKeyType.INT -> if (key.defaultValue !is Int) {
+            PersistentDataKeyType.INT -> if (default !is Int) {
                 throw IllegalArgumentException("Invalid Data Type! Should be Int")
             }
-            PersistentDataKeyType.DOUBLE -> if (key.defaultValue !is Double) {
+            PersistentDataKeyType.DOUBLE -> if (default !is Double) {
                 throw IllegalArgumentException("Invalid Data Type! Should be Double")
             }
-            PersistentDataKeyType.BOOLEAN -> if (key.defaultValue !is Boolean) {
+            PersistentDataKeyType.BOOLEAN -> if (default !is Boolean) {
                 throw IllegalArgumentException("Invalid Data Type! Should be Boolean")
             }
-            PersistentDataKeyType.STRING -> if (key.defaultValue !is String) {
+            PersistentDataKeyType.STRING -> if (default !is String) {
                 throw IllegalArgumentException("Invalid Data Type! Should be String")
             }
+            PersistentDataKeyType.STRING_LIST -> if (default !is List<*> || default.firstOrNull() !is String?) {
+                throw IllegalArgumentException("Invalid Data Type! Should be String List")
+            }
 
             else -> throw NullPointerException("Null value found!")
         }