diff --git a/src/pivutil.rs b/src/pivutil.rs
index d7c4ec8..63a5d26 100644
--- a/src/pivutil.rs
+++ b/src/pivutil.rs
@@ -55,35 +55,32 @@ pub fn slot_equals(slot_id: &SlotId, slot: &str) -> bool {
 }
 
 pub fn get_slot_id(slot: &str) -> XResult<SlotId> {
-    Ok(match slot {
-        "9a" => SlotId::Authentication,
-        "9c" => SlotId::Signature,
-        "9d" => SlotId::KeyManagement,
-        "9e" => SlotId::CardAuthentication,
-        "r1" | "R1" => SlotId::Retired(RetiredSlotId::R1),
-        "r2" | "R2" => SlotId::Retired(RetiredSlotId::R2),
-        "r3" | "R3" => SlotId::Retired(RetiredSlotId::R3),
-        "r4" | "R4" => SlotId::Retired(RetiredSlotId::R4),
-        "r5" | "R5" => SlotId::Retired(RetiredSlotId::R5),
-        "r6" | "R6" => SlotId::Retired(RetiredSlotId::R6),
-        "r7" | "R7" => SlotId::Retired(RetiredSlotId::R7),
-        "r8" | "R8" => SlotId::Retired(RetiredSlotId::R8),
-        "r9" | "R9" => SlotId::Retired(RetiredSlotId::R9),
-        "r10" | "R10" => SlotId::Retired(RetiredSlotId::R10),
-        "r11" | "R11" => SlotId::Retired(RetiredSlotId::R11),
-        "r12" | "R12" => SlotId::Retired(RetiredSlotId::R12),
-        "r13" | "R13" => SlotId::Retired(RetiredSlotId::R13),
-        "r14" | "R14" => SlotId::Retired(RetiredSlotId::R14),
-        "r15" | "R15" => SlotId::Retired(RetiredSlotId::R15),
-        "r16" | "R16" => SlotId::Retired(RetiredSlotId::R16),
-        "r17" | "R17" => SlotId::Retired(RetiredSlotId::R17),
-        "r18" | "R18" => SlotId::Retired(RetiredSlotId::R18),
-        "r19" | "R19" => SlotId::Retired(RetiredSlotId::R19),
-        "r20" | "R20" => SlotId::Retired(RetiredSlotId::R20),
-        _ => {
-            let retired_slot_id = opt_result!(RetiredSlotId::from_str(slot), "Slot not found: {}");
-            debugging!("Retried slot id: {}", retired_slot_id);
-            SlotId::Retired(retired_slot_id)
-        }
+    let slot_lower = slot.to_lowercase();
+    Ok(match slot_lower.as_str() {
+        "9a" | "auth" | "authentication" => SlotId::Authentication,
+        "9c" | "sign" | "signature" => SlotId::Signature,
+        "9d" | "keym" | "keymanagement" => SlotId::KeyManagement,
+        "9e" | "card" | "cardauthentication" => SlotId::CardAuthentication,
+        "r1" | "82" => SlotId::Retired(RetiredSlotId::R1),
+        "r2" | "83" => SlotId::Retired(RetiredSlotId::R2),
+        "r3" | "84" => SlotId::Retired(RetiredSlotId::R3),
+        "r4" | "85" => SlotId::Retired(RetiredSlotId::R4),
+        "r5" | "86" => SlotId::Retired(RetiredSlotId::R5),
+        "r6" | "87" => SlotId::Retired(RetiredSlotId::R6),
+        "r7" | "88" => SlotId::Retired(RetiredSlotId::R7),
+        "r8" | "89" => SlotId::Retired(RetiredSlotId::R8),
+        "r9" | "8a" => SlotId::Retired(RetiredSlotId::R9),
+        "r10" | "8b" => SlotId::Retired(RetiredSlotId::R10),
+        "r11" | "8c" => SlotId::Retired(RetiredSlotId::R11),
+        "r12" | "8d" => SlotId::Retired(RetiredSlotId::R12),
+        "r13" | "8e" => SlotId::Retired(RetiredSlotId::R13),
+        "r14" | "8f" => SlotId::Retired(RetiredSlotId::R14),
+        "r15" | "90" => SlotId::Retired(RetiredSlotId::R15),
+        "r16" | "91" => SlotId::Retired(RetiredSlotId::R16),
+        "r17" | "92" => SlotId::Retired(RetiredSlotId::R17),
+        "r18" | "93" => SlotId::Retired(RetiredSlotId::R18),
+        "r19" | "94" => SlotId::Retired(RetiredSlotId::R19),
+        "r20" | "95" => SlotId::Retired(RetiredSlotId::R20),
+        _ => return simple_error!("Unknown slot: {}", slot),
     })
 }
\ No newline at end of file