diff --git a/modules/openid-federation-client/src/commonMain/kotlin/com/sphereon/oid/fed/client/mapper/JsonMapper.kt b/modules/openid-federation-client/src/commonMain/kotlin/com/sphereon/oid/fed/client/mapper/JsonMapper.kt
index 5cd3c302..d99c2c48 100644
--- a/modules/openid-federation-client/src/commonMain/kotlin/com/sphereon/oid/fed/client/mapper/JsonMapper.kt
+++ b/modules/openid-federation-client/src/commonMain/kotlin/com/sphereon/oid/fed/client/mapper/JsonMapper.kt
@@ -34,8 +34,8 @@ fun decodeJWTComponents(jwtToken: String): JWT {
         throw InvalidJwtException("Invalid JWT format: Expected 3 parts, found ${parts.size}")
     }
 
-    val headerJson = Base64.decode(parts[0]).decodeToString()
-    val payloadJson = Base64.decode(parts[1]).decodeToString()
+    val headerJson = Base64.UrlSafe.decode(parts[0]).decodeToString()
+    val payloadJson = Base64.UrlSafe.decode(parts[1]).decodeToString()
 
     return try {
         JWT(
diff --git a/modules/openid-federation-client/src/commonMain/kotlin/com/sphereon/oid/fed/client/trustchain/TrustChain.kt b/modules/openid-federation-client/src/commonMain/kotlin/com/sphereon/oid/fed/client/trustchain/TrustChain.kt
index 05fec6f0..93165a0d 100644
--- a/modules/openid-federation-client/src/commonMain/kotlin/com/sphereon/oid/fed/client/trustchain/TrustChain.kt
+++ b/modules/openid-federation-client/src/commonMain/kotlin/com/sphereon/oid/fed/client/trustchain/TrustChain.kt
@@ -272,7 +272,7 @@ class DefaultTrustChainImpl(
                 if (result != null) return result
                 chain.removeLast()
             }
-        } catch (_: Exception) {
+        } catch (_: Exception) { // TODO distinguish between remote HTTP errors and internal errors
             return null
         }