diff --git a/rvfi/insns/README.md b/rvfi/insns/README.md
index c538a19..26abcbf 100644
--- a/rvfi/insns/README.md
+++ b/rvfi/insns/README.md
@@ -129,8 +129,8 @@ The following core-specific parameters are currently supported:
 
 | Parameter | Description | Valid value(s) |
 | --- | --- | --- |
-| `params.ilen` | Max length of instruction retired by core | `32` |
-| `params.xlen` | Width of integer registers | `32` |
+| `params.ilen` | Max length of instruction retired by core | `32`, `64` |
+| `params.xlen` | Width of integer registers | `32`, `64` |
 | `params.csr_misa` | Support for MISA CSRs enabled | `True`, `False` |
 | `params.compressed` | Support for compressed instructions | `True`, `False` |
 | `params.aligned_mem` | Require aligned memory accesses | `True`, `False` |