diff --git a/include/mbedtls/entropy.h b/include/mbedtls/entropy.h
index fed0494..fb7f2f4 100644
--- a/include/mbedtls/entropy.h
+++ b/include/mbedtls/entropy.h
@@ -258,6 +258,15 @@
  * \return         0 if successful, or 1 if a test failed
  */
 int mbedtls_entropy_self_test( int verbose );
+
+#if !defined(MBEDTLS_TEST_NULL_ENTROPY) && defined(MBEDTLS_ENTROPY_HARDWARE_ALT)
+/**
+ * \brief          Checkup routine
+ *
+ * \return         0 if successful, or 1 if a test failed
+ */
+int mbedtls_entropy_self_test_bias( int verbose );
+#endif /* !MBEDTLS_TEST_NULL_ENTROPY && MBEDTLS_ENTROPY_HARDWARE_ALT */
 #endif /* MBEDTLS_SELF_TEST */
 
 #ifdef __cplusplus