diff --git a/app-common/src/main/java/im/angry/openeuicc/util/ActivationCode.kt b/app-common/src/main/java/im/angry/openeuicc/util/ActivationCode.kt
index fbecfae..ec59d36 100644
--- a/app-common/src/main/java/im/angry/openeuicc/util/ActivationCode.kt
+++ b/app-common/src/main/java/im/angry/openeuicc/util/ActivationCode.kt
@@ -7,9 +7,9 @@ data class ActivationCode(
     val confirmationCodeRequired: Boolean = false,
 ) {
     companion object {
-        fun fromString(token: String): ActivationCode {
-            val input = if (token.startsWith("LPA:", true)) token.drop(4) else token
-            val components = input.split('$').map { it.trim().ifEmpty { null } }
+        fun fromString(input: String): ActivationCode {
+            check(input.startsWith("LPA:", ignoreCase = true)) { "Invalid activation code format" }
+            val components = input.drop(4).split('$').map { it.trim().ifEmpty { null } }
             check(components.size >= 2) { "Invalid activation code format" }
             check(components[0] == "1") { "Invalid activation code version" }
             return ActivationCode(