diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index a948577b9..3890f470e 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -9,8 +9,7 @@ jobs:
     strategy:
       matrix:
         rust: [
-          1.31.0, # 2018!
-          1.36.0, # alloc, rand
+          1.60.0, # MSRV
           stable,
           beta,
           nightly
@@ -29,8 +28,8 @@ jobs:
       - run: ./ci/test_full.sh
 
   # try a target that doesn't have std at all, but does have alloc
-  no_std_stable:
-    name: No Std (stable)
+  no_std:
+    name: No Std
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
@@ -39,22 +38,6 @@ jobs:
           target: thumbv6m-none-eabi
       - run: cargo build --target thumbv6m-none-eabi --no-default-features --features "alloc libm serde rand"
 
-  # try a target that doesn't have std at all, nor alloc
-  no_std_131:
-    name: No Std (1.31.0)
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - uses: actions/cache@v4
-        with:
-          path: ~/.cargo/registry/index
-          key: cargo-1.31.0-git-index
-      - uses: dtolnay/rust-toolchain@1.31.0
-        with:
-          target: thumbv6m-none-eabi
-      - run: cargo generate-lockfile && cargo update -p libm --precise 0.2.5
-      - run: cargo build --target thumbv6m-none-eabi --no-default-features --features "libm"
-
   fmt:
     name: Format
     runs-on: ubuntu-latest
@@ -70,7 +53,7 @@ jobs:
   success:
     name: Success
     runs-on: ubuntu-latest
-    needs: [test, no_std_131, no_std_stable, fmt]
+    needs: [test, no_std, fmt]
     # Github branch protection is exceedingly silly and treats "jobs skipped because a dependency
     # failed" as success. So we have to do some contortions to ensure the job fails if any of its
     # dependencies fails.
diff --git a/.github/workflows/master.yaml b/.github/workflows/master.yaml
index 68c4900de..034e37936 100644
--- a/.github/workflows/master.yaml
+++ b/.github/workflows/master.yaml
@@ -13,7 +13,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        rust: [1.31.0, stable]
+        rust: [1.60.0, stable]
     steps:
       - uses: actions/checkout@v4
       - uses: actions/cache@v4
diff --git a/.github/workflows/pr.yaml b/.github/workflows/pr.yaml
index 787f90816..baac64847 100644
--- a/.github/workflows/pr.yaml
+++ b/.github/workflows/pr.yaml
@@ -9,7 +9,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        rust: [1.31.0, stable]
+        rust: [1.60.0, stable]
     steps:
       - uses: actions/checkout@v4
       - uses: actions/cache@v4
diff --git a/Cargo.toml b/Cargo.toml
index 06575a1c8..ac07a38df 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -8,26 +8,24 @@ categories = [ "algorithms", "data-structures", "science", "no-std" ]
 license = "MIT OR Apache-2.0"
 repository = "https://github.com/rust-num/num"
 name = "num"
-version = "0.4.2"
+version = "0.4.3"
 readme = "README.md"
 exclude = ["/ci/*", "/.github/*"]
-edition = "2018"
+edition = "2021"
+rust-version = "1.60"
 
 [package.metadata.docs.rs]
 features = ["std", "serde", "rand"]
 
-[badges]
-travis-ci = { repository = "rust-num/num" }
-
 [dependencies]
 
 [dependencies.num-bigint]
-optional = true # needs std until Rust 1.36
-version = "0.4.4"
+optional = true
+version = "0.4.5"
 default-features = false
 
 [dependencies.num-complex]
-version = "0.4.5"
+version = "0.4.6"
 default-features = false
 
 [dependencies.num-integer]
@@ -36,16 +34,16 @@ default-features = false
 features = ["i128"]
 
 [dependencies.num-iter]
-version = "0.1.44"
+version = "0.1.45"
 default-features = false
 features = ["i128"]
 
 [dependencies.num-rational]
-version = "0.4.1"
+version = "0.4.2"
 default-features = false
 
 [dependencies.num-traits]
-version = "0.2.18"
+version = "0.2.19"
 default-features = false
 features = ["i128"]
 
@@ -54,8 +52,10 @@ features = ["i128"]
 [features]
 default = ["std"]
 
+num-bigint = ["dep:num-bigint"]
+
 std = [
-  "num-bigint/std",
+  "dep:num-bigint", "num-bigint/std",
   "num-complex/std",
   "num-integer/std",
   "num-iter/std",
@@ -63,7 +63,7 @@ std = [
   "num-traits/std",
 ]
 
-alloc = ["num-bigint", "num-rational/num-bigint"]
+alloc = ["dep:num-bigint", "num-rational/num-bigint"]
 
 libm = [
   "num-complex/libm",
diff --git a/README.md b/README.md
index 0753d24f7..f9ab46cfc 100644
--- a/README.md
+++ b/README.md
@@ -2,7 +2,7 @@
 
 [![crate](https://img.shields.io/crates/v/num.svg)](https://crates.io/crates/num)
 [![documentation](https://docs.rs/num/badge.svg)](https://docs.rs/num)
-[![minimum rustc 1.31](https://img.shields.io/badge/rustc-1.31+-red.svg)](https://rust-lang.github.io/rfcs/2495-min-rust-version.html)
+[![minimum rustc 1.60](https://img.shields.io/badge/rustc-1.60+-red.svg)](https://rust-lang.github.io/rfcs/2495-min-rust-version.html)
 [![build status](https://github.com/rust-num/num/workflows/master/badge.svg)](https://github.com/rust-num/num/actions)
 
 A collection of numeric types and traits for Rust.
@@ -69,7 +69,7 @@ Release notes are available in [RELEASES.md](RELEASES.md).
 
 ## Compatibility
 
-The `num` crate as a whole is tested for rustc 1.31 and greater.
+The `num` crate as a whole is tested for rustc 1.60 and greater.
 
 The `num-traits`, `num-integer`, and `num-iter` crates are individually tested
 for rustc 1.8 and greater, if you require such older compatibility.
diff --git a/RELEASES.md b/RELEASES.md
index c32baea96..4fcb1a45a 100644
--- a/RELEASES.md
+++ b/RELEASES.md
@@ -1,3 +1,8 @@
+# Release 0.4.3 (2024-05-08)
+
+- Upgrade to 2021 edition, **MSRV 1.60**.
+- Updated all sub-crates to their latest versions.
+
 # Release 0.4.2 (2024-04-12)
 
 - Updated all sub-crates to their latest versions.
diff --git a/ci/rustup.sh b/ci/rustup.sh
index e59257bce..6cfe67ef0 100755
--- a/ci/rustup.sh
+++ b/ci/rustup.sh
@@ -5,6 +5,6 @@
 set -ex
 
 ci=$(dirname $0)
-for version in 1.31.0 1.36.0 stable beta nightly; do
+for version in 1.60.0 stable beta nightly; do
     rustup run "$version" "$ci/test_full.sh"
 done
diff --git a/ci/test_full.sh b/ci/test_full.sh
index f43635be9..6a361e07f 100755
--- a/ci/test_full.sh
+++ b/ci/test_full.sh
@@ -3,7 +3,7 @@
 set -e
 
 CRATE=num
-MSRV=1.31
+MSRV=1.60
 
 get_rust_version() {
   local array=($(rustc --version));
@@ -27,21 +27,15 @@ if ! check_version $MSRV ; then
   exit 1
 fi
 
-STD_FEATURES=(libm serde)
+STD_FEATURES=(libm serde rand)
+ALLOC_FEATURES=(libm serde rand)
 NO_STD_FEATURES=(libm)
-check_version 1.36 && STD_FEATURES+=(rand)
-check_version 1.36 && ALLOC_FEATURES=(libm serde rand)
 echo "Testing supported features: ${STD_FEATURES[*]}"
+echo "  alloc supported features: ${ALLOC_FEATURES[*]}"
 echo " no_std supported features: ${NO_STD_FEATURES[*]}"
-if [ -n "${ALLOC_FEATURES[*]}" ]; then
-  echo "  alloc supported features: ${ALLOC_FEATURES[*]}"
-fi
 
 cargo generate-lockfile
 
-# libm 0.2.6 started using {float}::EPSILON
-check_version 1.43 || cargo update -p libm --precise 0.2.5
-
 set -x
 
 # test the default with std
@@ -74,18 +68,16 @@ cargo build --no-default-features --features="${NO_STD_FEATURES[*]}"
 cargo test --no-default-features --features="${NO_STD_FEATURES[*]}"
 
 
-if [ -n "${ALLOC_FEATURES[*]}" ]; then
-  # test minimal with alloc
-  cargo build --no-default-features --features="alloc"
-  cargo test --no-default-features --features="alloc"
+# test minimal with alloc
+cargo build --no-default-features --features="alloc"
+cargo test --no-default-features --features="alloc"
 
-  # test each isolated feature with alloc
-  for feature in ${ALLOC_FEATURES[*]}; do
-    cargo build --no-default-features --features="alloc $feature"
-    cargo test --no-default-features --features="alloc $feature"
-  done
+# test each isolated feature with alloc
+for feature in ${ALLOC_FEATURES[*]}; do
+  cargo build --no-default-features --features="alloc $feature"
+  cargo test --no-default-features --features="alloc $feature"
+done
 
-  # test all supported features with alloc
-  cargo build --no-default-features --features="alloc ${ALLOC_FEATURES[*]}"
-  cargo test --no-default-features --features="alloc ${ALLOC_FEATURES[*]}"
-fi
+# test all supported features with alloc
+cargo build --no-default-features --features="alloc ${ALLOC_FEATURES[*]}"
+cargo test --no-default-features --features="alloc ${ALLOC_FEATURES[*]}"
diff --git a/src/lib.rs b/src/lib.rs
index f5c6535de..34b247fbd 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -54,7 +54,7 @@
 //!
 //! ## Compatibility
 //!
-//! The `num` crate is tested for rustc 1.31 and greater.
+//! The `num` crate is tested for rustc 1.60 and greater.
 
 #![doc(html_root_url = "https://docs.rs/num/0.4")]
 #![no_std]