diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5e69141e..f2c04ae0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -14,6 +14,7 @@ and this project adheres to Rust's notion of
   - `FullViewingKey::scope_for_address`
 
 ### Changed
+- Migrated to `halo2_proofs 0.1.0-beta.4`.
 - `orchard::builder`:
   - `Builder::add_spend` now requires that the `FullViewingKey` matches the
     given `Note`, and handles any scoping itself (instead of requiring the
diff --git a/Cargo.toml b/Cargo.toml
index 6400899e..a9e81b34 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -23,15 +23,13 @@ rustdoc-args = ["--cfg", "docsrs", "--html-in-header", "katex-header.html"]
 
 [dependencies]
 aes = "0.7"
-arrayvec = "0.7.0"
-bigint = "4"
 bitvec = "0.22"
 blake2b_simd = "1"
 ff = "0.11"
 fpe = "0.5"
 group = "0.11"
-halo2_gadgets = "=0.1.0-beta.2"
-halo2_proofs = "=0.1.0-beta.3"
+halo2_gadgets = "=0.1.0-beta.3"
+halo2_proofs = "=0.1.0-beta.4"
 lazy_static = "1"
 memuse = { version = "0.2", features = ["nonempty"] }
 pasta_curves = "0.3"
@@ -49,7 +47,7 @@ plotters = { version = "0.3.0", optional = true }
 
 [dev-dependencies]
 criterion = "0.3"
-halo2_gadgets = { version = "=0.1.0-beta.2", features = ["test-dependencies"] }
+halo2_gadgets = { version = "=0.1.0-beta.3", features = ["test-dependencies"] }
 hex = "0.4"
 proptest = "1.0.0"
 zcash_note_encryption = { version = "0.1", features = ["pre-zip-212"] }