diff --git a/ports/unix/mbedtls/mbedtls_config.h b/ports/unix/mbedtls/mbedtls_config.h
index 629064abc..f76a9cbf7 100644
--- a/ports/unix/mbedtls/mbedtls_config.h
+++ b/ports/unix/mbedtls/mbedtls_config.h
@@ -29,6 +29,10 @@
 // Set mbedtls configuration
 #define MBEDTLS_CIPHER_MODE_CTR // needed for MICROPY_PY_CRYPTOLIB_CTR
 
+// Cert time validation
+#define MBEDTLS_HAVE_TIME
+#define MBEDTLS_HAVE_TIME_DATE
+
 // Enable mbedtls modules
 #define MBEDTLS_HAVEGE_C
 #define MBEDTLS_TIMING_C