diff --git a/scripts/data_files/error.fmt b/scripts/data_files/error.fmt
index 781e72a919..b75a9ab4ec 100644
--- a/scripts/data_files/error.fmt
+++ b/scripts/data_files/error.fmt
@@ -152,8 +152,4 @@ void mbedtls_strerror(int ret, char *buf, size_t buflen)
 
 #endif /* MBEDTLS_ERROR_C */
 
-#if defined(MBEDTLS_TEST_HOOKS)
-void (*mbedtls_test_hook_error_add)(int, int, const char *, int);
-#endif
-
 #endif /* MBEDTLS_ERROR_C || MBEDTLS_ERROR_STRERROR_DUMMY */
diff --git a/tests/src/helpers.c b/tests/src/helpers.c
index db50296e01..bf823fed3e 100644
--- a/tests/src/helpers.c
+++ b/tests/src/helpers.c
@@ -717,4 +717,9 @@ void mbedtls_test_err_add_check(int high, int low,
                           line, file);
     }
 }
+
+#if defined(MBEDTLS_TEST_HOOKS)
+void (*mbedtls_test_hook_error_add)(int, int, const char *, int);
+#endif
+
 #endif /* MBEDTLS_TEST_HOOKS */