diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 48a33c2f49fa..806bd2bfa440 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -156,7 +156,8 @@ jobs:
         # We pin to a specific commit for paranoia's sake.
         uses: dtolnay/rust-toolchain@e12eda571dc9a5ee5d58eecf4738ec291c66f295
         with:
-          toolchain: 1.58.1
+          # We use nightly so that it correctly groups together imports
+          toolchain: nightly-2022-12-01
           components: rustfmt
       - uses: Swatinem/rust-cache@v2
 
diff --git a/changelog.d/15188.misc b/changelog.d/15188.misc
new file mode 100644
index 000000000000..e4e9472f0108
--- /dev/null
+++ b/changelog.d/15188.misc
@@ -0,0 +1 @@
+Use nightly rustfmt in CI.
diff --git a/rust/benches/evaluator.rs b/rust/benches/evaluator.rs
index 7c987d4948e0..44477e63f783 100644
--- a/rust/benches/evaluator.rs
+++ b/rust/benches/evaluator.rs
@@ -14,6 +14,7 @@
 
 #![feature(test)]
 use std::collections::BTreeSet;
+
 use synapse::push::{
     evaluator::PushRuleEvaluator, Condition, EventMatchCondition, FilteredPushRules, JsonValue,
     PushRules, SimpleJsonValue,
diff --git a/rust/src/push/evaluator.rs b/rust/src/push/evaluator.rs
index 55846627cca3..1c2a05ad9a7c 100644
--- a/rust/src/push/evaluator.rs
+++ b/rust/src/push/evaluator.rs
@@ -15,7 +15,6 @@
 use std::borrow::Cow;
 use std::collections::BTreeMap;
 
-use crate::push::{EventMatchPatternType, JsonValue};
 use anyhow::{Context, Error};
 use lazy_static::lazy_static;
 use log::warn;
@@ -27,6 +26,7 @@ use super::{
     Action, Condition, ExactEventMatchCondition, FilteredPushRules, KnownCondition,
     SimpleJsonValue,
 };
+use crate::push::{EventMatchPatternType, JsonValue};
 
 lazy_static! {
     /// Used to parse the `is` clause in the room member count condition.