diff --git a/include/mbedtls/bignum.h b/include/mbedtls/bignum.h
index 31383b1..4b579b0 100644
--- a/include/mbedtls/bignum.h
+++ b/include/mbedtls/bignum.h
@@ -758,6 +758,8 @@
                    int (*f_rng)(void *, unsigned char *, size_t),
                    void *p_rng );
 
+#if defined(MBEDTLS_SELF_TEST)
+
 /**
  * \brief          Checkup routine
  *
@@ -765,6 +767,8 @@
  */
 int mbedtls_mpi_self_test( int verbose );
 
+#endif /* MBEDTLS_SELF_TEST */
+
 #ifdef __cplusplus
 }
 #endif