diff --git a/include/mbedtls/ctr_drbg.h b/include/mbedtls/ctr_drbg.h
index dcbc047..dda356e 100644
--- a/include/mbedtls/ctr_drbg.h
+++ b/include/mbedtls/ctr_drbg.h
@@ -310,6 +310,8 @@
 int mbedtls_ctr_drbg_update_seed_file( mbedtls_ctr_drbg_context *ctx, const char *path );
 #endif /* MBEDTLS_FS_IO */
 
+#if defined(MBEDTLS_SELF_TEST)
+
 /**
  * \brief               The CTR_DRBG checkup routine.
  *
@@ -318,6 +320,8 @@
  */
 int mbedtls_ctr_drbg_self_test( int verbose );
 
+#endif /* MBEDTLS_SELF_TEST */
+
 /* Internal functions (do not call directly) */
 int mbedtls_ctr_drbg_seed_entropy_len( mbedtls_ctr_drbg_context *,
                                int (*)(void *, unsigned char *, size_t), void *,