diff --git a/draft-irtf-cfrg-vdaf.md b/draft-irtf-cfrg-vdaf.md
index c5fbc6cf..d492b8bd 100644
--- a/draft-irtf-cfrg-vdaf.md
+++ b/draft-irtf-cfrg-vdaf.md
@@ -4569,12 +4569,13 @@ as needed.
 ## Construction {#poplar1-construction}
 
 This section specifies `Poplar1`, an implementation of the `Vdaf` interface
-({{vdaf}}). It is defined in terms of any `Idpf` ({{idpf}}) for which
-`SHARES == 2` and `VALUE_LEN == 2` and an implementation of `Xof`
-({{xof}}). The associated constants and types required by the `Vdaf` interface
-are defined in {{poplar1-param}}. The methods required for sharding,
-preparation, aggregation, and unsharding are described in the remaining
-subsections. These methods make use of constants defined in {{poplar1-const}}.
+({{vdaf}}). It is defined in terms of the `Idpf` implementation of
+{{idpf-bbcggi21}} with `SHARES == 2` and `VALUE_LEN == 2` and
+`XofTurboShake128` as specified in {{xof-turboshake128}}. The associated
+constants and types required by the `Vdaf` interface are defined in
+{{poplar1-param}}. The methods required for sharding, preparation, aggregation,
+and unsharding are described in the remaining subsections. These methods make
+use of constants defined in {{poplar1-const}}.
 
 | Parameter         | Value                                      |
 |:------------------|:-------------------------------------------|