diff --git a/include/mbedtls/entropy_poll.h b/include/mbedtls/entropy_poll.h
index d7aa88c..430e865 100644
--- a/include/mbedtls/entropy_poll.h
+++ b/include/mbedtls/entropy_poll.h
@@ -47,7 +47,7 @@
  * \brief           Entropy poll callback that provides 0 entropy.
  */
 #if defined(MBEDTLS_TEST_NULL_ENTROPY)
-    int mbedtls_zero_entropy_poll( void *data,
+    int mbedtls_null_entropy_poll( void *data,
                                 unsigned char *output, size_t len, size_t *olen );
 #endif