diff --git a/include/haproxy/uri_normalizer-t.h b/include/haproxy/uri_normalizer-t.h
new file mode 100644
index 0000000..bcbcaef
--- /dev/null
+++ b/include/haproxy/uri_normalizer-t.h
@@ -0,0 +1,31 @@
+/*
+ * include/haproxy/uri_normalizer.h
+ * HTTP request URI normalization.
+ *
+ * Copyright 2021 Tim Duesterhus <tim@bastelstu.be>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ */
+
+#ifndef _HAPROXY_URI_NORMALIZER_T_H
+#define _HAPROXY_URI_NORMALIZER_T_H
+
+enum uri_normalizer_err {
+	URI_NORMALIZER_ERR_NONE = 0,
+	URI_NORMALIZER_ERR_ALLOC,
+	URI_NORMALIZER_ERR_INVALID_INPUT,
+	URI_NORMALIZER_ERR_INTERNAL_ERROR = 0xdead,
+};
+
+#endif /* _HAPROXY_URI_NORMALIZER_T_H */
+
+/*
+ * Local variables:
+ *  c-indent-level: 8
+ *  c-basic-offset: 8
+ * End:
+ */
diff --git a/include/haproxy/uri_normalizer.h b/include/haproxy/uri_normalizer.h
index 82ef973..20341a9 100644
--- a/include/haproxy/uri_normalizer.h
+++ b/include/haproxy/uri_normalizer.h
@@ -14,6 +14,8 @@
 #ifndef _HAPROXY_URI_NORMALIZER_H
 #define _HAPROXY_URI_NORMALIZER_H
 
+#include <haproxy/uri_normalizer-t.h>
+
 #endif /* _HAPROXY_URI_NORMALIZER_H */
 
 /*