diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 966cc8da..162cd813 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -14,7 +14,7 @@ jobs:
       - uses: actions/checkout@v2
       - uses: actions-rs/toolchain@v1
         with:
-          toolchain: 1.56.1
+          toolchain: 1.60.0
           override: true
       - name: Run tests
         uses: actions-rs/cargo@v1
@@ -30,7 +30,7 @@ jobs:
       - uses: actions/checkout@v2
       - uses: actions-rs/toolchain@v1
         with:
-          toolchain: 1.56.1
+          toolchain: 1.60.0
           override: true
       # Build benchmarks to prevent bitrot
       - name: Build benchmarks
@@ -46,7 +46,7 @@ jobs:
       - uses: actions/checkout@v2
       - uses: actions-rs/toolchain@v1
         with:
-          toolchain: 1.56.1
+          toolchain: 1.60.0
           override: true
       - name: Setup mdBook
         uses: peaceiris/actions-mdbook@v1
@@ -89,7 +89,7 @@ jobs:
       - uses: actions/checkout@v2
       - uses: actions-rs/toolchain@v1
         with:
-          toolchain: 1.56.1
+          toolchain: 1.60.0
           override: true
       - name: cargo fetch
         uses: actions-rs/cargo@v1
@@ -112,7 +112,7 @@ jobs:
       - uses: actions/checkout@v2
       - uses: actions-rs/toolchain@v1
         with:
-          toolchain: 1.56.1
+          toolchain: 1.60.0
           override: true
       - run: rustup component add rustfmt
       - uses: actions-rs/cargo@v1
diff --git a/.github/workflows/lints-stable.yml b/.github/workflows/lints-stable.yml
index 242041e8..69d6e15c 100644
--- a/.github/workflows/lints-stable.yml
+++ b/.github/workflows/lints-stable.yml
@@ -5,19 +5,19 @@ on: pull_request
 
 jobs:
   clippy:
-    name: Clippy (1.56.1)
+    name: Clippy (1.60.0)
     timeout-minutes: 30
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
       - uses: actions-rs/toolchain@v1
         with:
-          toolchain: 1.56.1
+          toolchain: 1.60.0
           components: clippy
           override: true
       - name: Run Clippy
         uses: actions-rs/clippy-check@v1
         with:
-          name: Clippy (1.56.1)
+          name: Clippy (1.60.0)
           token: ${{ secrets.GITHUB_TOKEN }}
           args: --all-features --all-targets -- -D warnings
diff --git a/CHANGELOG.md b/CHANGELOG.md
index a553528a..bd61c977 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -14,6 +14,7 @@ and this project adheres to Rust's notion of
   - `OutputError` 
 
 ### Changed
+- MSRV is now 1.60.0.
 - `orchard::builder`:
   - `Builder::{add_spend, add_output}` now use concrete error types instead of
     `&'static str`s.
diff --git a/Cargo.toml b/Cargo.toml
index 813b0aee..61c12692 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -9,7 +9,7 @@ authors = [
     "Kris Nuttycombe <kris@electriccoin.co>",
 ]
 edition = "2021"
-rust-version = "1.56.1"
+rust-version = "1.60"
 description = "The Orchard shielded transaction protocol"
 license-file = "LICENSE-BOSL"
 repository = "https://github.com/zcash/orchard"
@@ -48,6 +48,7 @@ incrementalmerkletree = "0.3"
 tracing = "0.1"
 
 # Developer tooling dependencies
+image = { version = ">= 0.24, < 0.24.5", optional = true } # 0.24.5 has MSRV 1.61
 plotters = { version = "0.3.0", optional = true }
 
 [dev-dependencies]
@@ -58,13 +59,14 @@ proptest = "1.0.0"
 zcash_note_encryption = { version = "0.2", features = ["pre-zip-212"] }
 
 [target.'cfg(unix)'.dev-dependencies]
+inferno = ">= 0.11, < 0.11.15"
 pprof = { version = "0.9", features = ["criterion", "flamegraph"] } # MSRV 1.56
 
 [lib]
 bench = false
 
 [features]
-dev-graph = ["halo2_proofs/dev-graph", "plotters"]
+dev-graph = ["halo2_proofs/dev-graph", "image", "plotters"]
 test-dependencies = ["proptest"]
 
 [[bench]]
diff --git a/README.md b/README.md
index 12b74651..babbd341 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 # orchard [![Crates.io](https://img.shields.io/crates/v/orchard.svg)](https://crates.io/crates/orchard) #
 
-Requires Rust 1.56.1+.
+Requires Rust 1.60+.
 
 ## Documentation
 
diff --git a/rust-toolchain b/rust-toolchain
deleted file mode 100644
index 43c989b5..00000000
--- a/rust-toolchain
+++ /dev/null
@@ -1 +0,0 @@
-1.56.1
diff --git a/rust-toolchain.toml b/rust-toolchain.toml
new file mode 100644
index 00000000..e06e5ca5
--- /dev/null
+++ b/rust-toolchain.toml
@@ -0,0 +1,3 @@
+[toolchain]
+channel = "1.60.0"
+components = [ "clippy", "rustfmt" ]
diff --git a/src/builder.rs b/src/builder.rs
index 2ccc3058..0f95fb3b 100644
--- a/src/builder.rs
+++ b/src/builder.rs
@@ -49,7 +49,7 @@ impl Display for BuildError {
         use BuildError::*;
         match self {
             MissingSignatures => f.write_str("Required signatures were missing during build"),
-            Proof(e) => f.write_str(&format!("Could not create proof: {}", e.to_string())),
+            Proof(e) => f.write_str(&format!("Could not create proof: {}", e)),
             ValueSum(_) => f.write_str("Overflow occurred during value construction"),
             InvalidExternalSignature => f.write_str("External signature was invalid"),
             DuplicateSignature => f.write_str("Signature valid for more than one input"),