diff --git a/Cargo.lock b/Cargo.lock
index d6f50b08a2..312039a490 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2388,9 +2388,9 @@ dependencies = [
 
 [[package]]
 name = "regalloc2"
-version = "0.4.2"
+version = "0.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "91b2eab54204ea0117fe9a060537e0b07a4e72f7c7d182361ecc346cab2240e5"
+checksum = "10b072c75d1b10368447a55cf1d589f2527d956e92c281c81c3e788cda81b983"
 dependencies = [
  "fxhash",
  "log",
diff --git a/cranelift/codegen/Cargo.toml b/cranelift/codegen/Cargo.toml
index 88a08f4f19..64be723b88 100644
--- a/cranelift/codegen/Cargo.toml
+++ b/cranelift/codegen/Cargo.toml
@@ -26,7 +26,7 @@ serde = { version = "1.0.94", features = ["derive"], optional = true }
 bincode = { version = "1.2.1", optional = true }
 gimli = { workspace = true, features = ["write"], optional = true }
 smallvec = { workspace = true }
-regalloc2 = { version = "0.4.2", features = ["checker"] }
+regalloc2 = { version = "0.5.0", features = ["checker"] }
 souper-ir = { version = "2.1.0", optional = true }
 sha2 = { version = "0.10.2", optional = true }
 # It is a goal of the cranelift-codegen crate to have minimal external dependencies.
diff --git a/cranelift/codegen/src/machinst/lower.rs b/cranelift/codegen/src/machinst/lower.rs
index 2cc2b9fe32..2b6480f280 100644
--- a/cranelift/codegen/src/machinst/lower.rs
+++ b/cranelift/codegen/src/machinst/lower.rs
@@ -25,7 +25,7 @@ use regalloc2::{MachineEnv, PRegSet};
 use smallvec::{smallvec, SmallVec};
 use std::fmt::Debug;
 
-use super::{preg_set_from_machine_env, VCodeBuildDirection, VRegAllocator};
+use super::{VCodeBuildDirection, VRegAllocator};
 
 /// An "instruction color" partitions CLIF instructions by side-effecting ops.
 /// All instructions with the same "color" are guaranteed not to be separated by
@@ -417,7 +417,7 @@ impl<'func, I: VCodeInst> Lower<'func, I> {
         Ok(Lower {
             f,
             flags,
-            allocatable: preg_set_from_machine_env(machine_env),
+            allocatable: PRegSet::from(machine_env),
             vcode,
             vregs,
             value_regs,
diff --git a/cranelift/codegen/src/machinst/reg.rs b/cranelift/codegen/src/machinst/reg.rs
index 32838fdab0..2d727559c9 100644
--- a/cranelift/codegen/src/machinst/reg.rs
+++ b/cranelift/codegen/src/machinst/reg.rs
@@ -4,7 +4,7 @@
 
 use alloc::{string::String, vec::Vec};
 use core::{fmt::Debug, hash::Hash};
-use regalloc2::{Allocation, MachineEnv, Operand, OperandConstraint, PReg, PRegSet, VReg};
+use regalloc2::{Allocation, Operand, OperandConstraint, PReg, PRegSet, VReg};
 
 #[cfg(feature = "enable-serde")]
 use serde::{Deserialize, Serialize};
@@ -38,26 +38,6 @@ pub fn first_user_vreg_index() -> usize {
     PINNED_VREGS
 }
 
-/// Collect the registers from a regalloc2 MachineEnv into a PRegSet.
-/// TODO: remove this once it's upstreamed in regalloc2
-pub fn preg_set_from_machine_env(machine_env: &MachineEnv) -> PRegSet {
-    let mut regs = PRegSet::default();
-
-    for class in machine_env.preferred_regs_by_class.iter() {
-        for reg in class.iter() {
-            regs.add(*reg);
-        }
-    }
-
-    for class in machine_env.non_preferred_regs_by_class.iter() {
-        for reg in class.iter() {
-            regs.add(*reg);
-        }
-    }
-
-    regs
-}
-
 /// A register named in an instruction. This register can be either a
 /// virtual register or a fixed physical register. It does not have
 /// any constraints applied to it: those can be added later in
diff --git a/supply-chain/audits.toml b/supply-chain/audits.toml
index 50097663f0..e7e799b31a 100644
--- a/supply-chain/audits.toml
+++ b/supply-chain/audits.toml
@@ -416,6 +416,12 @@ criteria = "safe-to-deploy"
 delta = "0.4.1 -> 0.4.2"
 notes = "The Bytecode Alliance is the author of this crate."
 
+[[audits.regalloc2]]
+who = "Trevor Elliott <telliott@fastly.com>"
+criteria = "safe-to-deploy"
+delta = "0.4.2 -> 0.5.0"
+notes = "The Bytecode Alliance is the author of this crate."
+
 [[audits.rustc-demangle]]
 who = "Alex Crichton <alex@alexcrichton.com>"
 criteria = "safe-to-deploy"
diff --git a/winch/codegen/Cargo.toml b/winch/codegen/Cargo.toml
index c7320485d6..c7c306d8fc 100644
--- a/winch/codegen/Cargo.toml
+++ b/winch/codegen/Cargo.toml
@@ -17,7 +17,7 @@ target-lexicon = { workspace = true, features = ["std"] }
 # In the next iteration we'll factor out the common bits so that they can be consumed
 # by Cranelift and Winch.
 cranelift-codegen = { workspace = true }
-regalloc2 = "0.4.2"
+regalloc2 = "0.5.0"
 
 [features]
 x64 = ["cranelift-codegen/x86"]