diff --git a/include/mbedtls/platform.h b/include/mbedtls/platform.h
index 10137d7..5fa01b5 100644
--- a/include/mbedtls/platform.h
+++ b/include/mbedtls/platform.h
@@ -76,6 +76,7 @@
 #if !defined(MBEDTLS_PLATFORM_STD_EXIT_FAILURE)
 #define MBEDTLS_PLATFORM_STD_EXIT_FAILURE  EXIT_FAILURE /**< Default exit value to use */
 #endif
+#if defined(MBEDTLS_FS_IO)
 #if !defined(MBEDTLS_PLATFORM_STD_NV_SEED_READ)
 #define MBEDTLS_PLATFORM_STD_NV_SEED_READ   mbedtls_platform_std_nv_seed_read
 #endif
@@ -85,6 +86,7 @@
 #if !defined(MBEDTLS_PLATFORM_STD_NV_SEED_FILE)
 #define MBEDTLS_PLATFORM_STD_NV_SEED_FILE   "seedfile"
 #endif
+#endif /* MBEDTLS_FS_IO */
 #else /* MBEDTLS_PLATFORM_NO_STD_FUNCTIONS */
 #if defined(MBEDTLS_PLATFORM_STD_MEM_HDR)
 #include MBEDTLS_PLATFORM_STD_MEM_HDR