diff --git a/scheme/base.sld b/scheme/base.sld
index 404ceea9..582e731c 100644
--- a/scheme/base.sld
+++ b/scheme/base.sld
@@ -56,6 +56,11 @@
     current-input-port
     current-error-port
     call-with-port
+    ; TODO: error-object?
+    ; TODO: error-object-message
+    ; TODO: error-object-irritants
+    ; TODO: file-error?
+    ; TODO: read-error?
     error
     raise
     raise-continuable