diff --git a/src/utility/SElementArduinoCloudCertificate.cpp b/src/utility/SElementArduinoCloudCertificate.cpp
index 0478aa1..e44ccd2 100644
--- a/src/utility/SElementArduinoCloudCertificate.cpp
+++ b/src/utility/SElementArduinoCloudCertificate.cpp
@@ -39,6 +39,7 @@ int SElementArduinoCloudCertificate::write(SecureElement & se, ECP256Certificate
 int SElementArduinoCloudCertificate::read(SecureElement & se, ECP256Certificate & cert, const SElementArduinoCloudSlot certSlot, const SElementArduinoCloudSlot keySlot)
 {
 #if defined(SECURE_ELEMENT_IS_SE050) || defined(SECURE_ELEMENT_IS_SOFTSE)
+  (void)keySlot;
   byte derBuffer[SE_CERT_BUFFER_LENGTH];
   size_t derLen;
   if (!se.readSlot(static_cast<int>(certSlot), derBuffer, sizeof(derBuffer))) {