diff --git a/scripts/data_files/error.fmt b/scripts/data_files/error.fmt
index 9e479bb..7fed598 100644
--- a/scripts/data_files/error.fmt
+++ b/scripts/data_files/error.fmt
@@ -82,6 +82,8 @@
     return( NULL );
 }
 
+void (*mbedtls_test_hook_error_add)( int, int, const char *, int );
+
 void mbedtls_strerror( int ret, char *buf, size_t buflen )
 {
     size_t len;