diff --git a/include/mbedtls/sha256.h b/include/mbedtls/sha256.h
index adf31a8..de19dc2 100644
--- a/include/mbedtls/sha256.h
+++ b/include/mbedtls/sha256.h
@@ -257,6 +257,8 @@
 #undef MBEDTLS_DEPRECATED
 #endif /* !MBEDTLS_DEPRECATED_REMOVED */
 
+#if defined(MBEDTLS_SELF_TEST)
+
 /**
  * \brief          The SHA-224 and SHA-256 checkup routine.
  *
@@ -265,6 +267,8 @@
  */
 int mbedtls_sha256_self_test( int verbose );
 
+#endif /* MBEDTLS_SELF_TEST */
+
 #ifdef __cplusplus
 }
 #endif