diff --git a/noisemeter-device/secret-store.cpp b/noisemeter-device/secret-store.cpp
index f2fa473..8532a4e 100644
--- a/noisemeter-device/secret-store.cpp
+++ b/noisemeter-device/secret-store.cpp
@@ -1,5 +1,8 @@
+#include "board.h"
 #include "secret-store.h"
 
+#if defined(BOARD_ESP32_PCB)
+
 #include <esp_hmac.h>
 #include <mbedtls/aes.h>
 
@@ -49,3 +52,21 @@ String decrypt(String key, String in)
 
 } // namespace Secret
 
+#else // !defined(BOARD_ESP32_PCB)
+
+namespace Secret {
+
+String encrypt([[maybe_unused]] String key, String in)
+{
+    return in;
+}
+
+String decrypt([[maybe_unused]] String key, String in)
+{
+    return in;
+}
+
+} // namespace Secret
+
+#endif // defined(BOARD_ESP32_PCB)
+