diff --git a/rust-toolchain.toml b/rust-toolchain.toml
index 99e619bb8..abc362744 100644
--- a/rust-toolchain.toml
+++ b/rust-toolchain.toml
@@ -1,3 +1,3 @@
 [toolchain]
-channel = "1.98.1"
+channel = "1.99.1"
 profile = "default"
diff --git a/src/asset/pool.rs b/src/asset/pool.rs
index 5b0fd9f18..741897513 100644
--- a/src/asset/pool.rs
+++ b/src/asset/pool.rs
@@ -231,7 +231,7 @@ mod tests {
 
     #[rstest]
     fn asset_pool_new() {
-        assert!(AssetPool::new().assets.is_empty());
+        assert_eq!(AssetPool::new().assets, []);
     }
 
     #[rstest]
@@ -263,9 +263,9 @@ mod tests {
         let commission_year = multi_tranche_asset.commission_year;
         let mut asset_pool = AssetPool::new();
         let mut user_assets = vec![multi_tranche_asset.into()];
-        assert!(asset_pool.assets.is_empty());
+        assert_eq!(asset_pool.assets, []);
         asset_pool.commission_new(commission_year, &mut user_assets);
-        assert!(user_assets.is_empty());
+        assert_eq!(user_assets, []);
         assert_eq!(asset_pool.assets.len(), 1);
         assert_eq!(asset_pool.next_id, 1);
     }
@@ -274,16 +274,16 @@ mod tests {
     fn asset_pool_commission_already_decommissioned(asset: Asset) {
         let year = asset.max_decommission_year();
         let mut asset_pool = AssetPool::new();
-        assert!(asset_pool.assets.is_empty());
+        assert_eq!(asset_pool.assets, []);
         asset_pool.commission_new(year, &mut vec![asset.into()]);
-        assert!(asset_pool.assets.is_empty());
+        assert_eq!(asset_pool.assets, []);
     }
 
     #[rstest]
     fn asset_pool_decommission_old(mut user_assets: Vec<UserAsset>) {
         let mut asset_pool = AssetPool::new();
         asset_pool.commission_new(2020, &mut user_assets);
-        assert!(user_assets.is_empty());
+        assert_eq!(user_assets, []);
         assert_eq!(asset_pool.assets.len(), 2);
 
         // should decommission first asset (lifetime == 5)
@@ -298,7 +298,7 @@ mod tests {
 
         // should decommission second asset
         asset_pool.decommission_old(2040);
-        assert!(asset_pool.assets.is_empty());
+        assert_eq!(asset_pool.assets, []);
     }
 
     #[rstest]
@@ -691,6 +691,6 @@ mod tests {
 
         asset_pool.decommission_mothballed(2025, 10);
 
-        assert!(asset_pool.assets.is_empty());
+        assert_eq!(asset_pool.assets, []);
     }
 }
diff --git a/src/example.rs b/src/example.rs
index e084976df..00414f424 100644
--- a/src/example.rs
+++ b/src/example.rs
@@ -76,7 +76,7 @@ mod tests {
                 .with_context(|| format!("Could not load readme for {example}"))
                 .unwrap();
 
-            assert!(!readme.trim().is_empty());
+            assert_ne!(readme.trim(), "");
         }
     }
 }
diff --git a/src/settings.rs b/src/settings.rs
index 6fe834e8e..538dfd838 100644
--- a/src/settings.rs
+++ b/src/settings.rs
@@ -165,6 +165,6 @@ mod tests {
 
     #[test]
     fn default_file_contents() {
-        assert!(!Settings::default_file_contents().is_empty());
+        assert_ne!(Settings::default_file_contents(), "");
     }
 }
diff --git a/src/simulation/investment.rs b/src/simulation/investment.rs
index 1340c402a..282e4b056 100644
--- a/src/simulation/investment.rs
+++ b/src/simulation/investment.rs
@@ -861,7 +861,7 @@ mod tests {
         // Check all assets are removed when `only_candidates` is false
         opt_assets.push(candidate_asset.clone().into());
         remove_assets_exceeding_agent_limits(&mut opt_assets, &limits, false);
-        assert!(opt_assets.is_empty());
+        assert_eq!(opt_assets, []);
     }
 
     #[rstest]
diff --git a/src/simulation/optimisation.rs b/src/simulation/optimisation.rs
index 3b42e591e..62e91f37c 100644
--- a/src/simulation/optimisation.rs
+++ b/src/simulation/optimisation.rs
@@ -124,7 +124,7 @@ impl VariableMap {
         model: &Model,
         markets_to_allow_unmet_demand: &[(CommodityID, RegionID)],
     ) {
-        assert!(!markets_to_allow_unmet_demand.is_empty());
+        assert_ne!(markets_to_allow_unmet_demand, []);
 
         // This line **must** come before we add more variables
         let start = problem.num_cols();
@@ -499,7 +499,7 @@ impl<'model, 'run> DispatchRun<'model, 'run> {
         self,
         markets_to_balance: &'run [(CommodityID, RegionID)],
     ) -> Self {
-        assert!(!markets_to_balance.is_empty());
+        assert_ne!(markets_to_balance, []);
 
         Self {
             markets_to_balance,
diff --git a/src/simulation/optimisation/constraints.rs b/src/simulation/optimisation/constraints.rs
index fd233408a..d98bd8f5b 100644
--- a/src/simulation/optimisation/constraints.rs
+++ b/src/simulation/optimisation/constraints.rs
@@ -683,7 +683,10 @@ mod tests {
 
     #[test]
     fn groups_no_assets() {
-        assert!(group_dispatch_equivalent_assets(std::iter::empty()).is_empty());
+        assert_eq!(
+            group_dispatch_equivalent_assets(std::iter::empty()),
+            [] as [std::vec::Vec<&AssetRef>; 0]
+        );
     }
 
     #[rstest]
diff --git a/tests/cli.rs b/tests/cli.rs
index 28796b9ec..4a51ba3aa 100644
--- a/tests/cli.rs
+++ b/tests/cli.rs
@@ -100,7 +100,7 @@ fn check_example_list_command(#[case] patch: bool) {
 /// Test the `example info` command
 #[test]
 fn check_example_info_command() {
-    assert!(!get_muse2_stdout(&["example", "info", EXAMPLE_NAME]).is_empty());
+    assert_ne!(get_muse2_stdout(&["example", "info", EXAMPLE_NAME]), "");
 }
 
 #[test]