diff --git a/rust-toolchain b/rust-toolchain
index 902c741..4934985 100644
--- a/rust-toolchain
+++ b/rust-toolchain
@@ -1 +1 @@
-1.65.0
+1.69.0
diff --git a/src/assignments/assignment09_grade.rs b/src/assignments/assignment09_grade.rs
index 49480b5..ed8c293 100644
--- a/src/assignments/assignment09_grade.rs
+++ b/src/assignments/assignment09_grade.rs
@@ -4,19 +4,19 @@ mod test {
 
     #[test]
     fn test_is_fibonacci() {
-        assert_eq!(is_fibonacci([1, 1, 2, 3, 5, 8, 13].into_iter()), true);
-        assert_eq!(is_fibonacci([1, 1, 2, 3, 5, 8, 14].into_iter()), false);
-        assert_eq!(is_fibonacci([2, 4, 6, 10, 16, 26].into_iter()), true);
-        assert_eq!(is_fibonacci([4, 9, 13, 22, 35].into_iter()), true);
-        assert_eq!(is_fibonacci([0, 0, 0, 0, 0].into_iter()), true);
-        assert_eq!(is_fibonacci([1, 1].into_iter()), true);
-        assert_eq!(is_fibonacci([1].into_iter()), true);
-        assert_eq!(is_fibonacci([].into_iter()), true);
+        assert!(is_fibonacci([1, 1, 2, 3, 5, 8, 13].into_iter()));
+        assert!(!is_fibonacci([1, 1, 2, 3, 5, 8, 14].into_iter()));
+        assert!(is_fibonacci([2, 4, 6, 10, 16, 26].into_iter()));
+        assert!(is_fibonacci([4, 9, 13, 22, 35].into_iter()));
+        assert!(is_fibonacci([0, 0, 0, 0, 0].into_iter()));
+        assert!(is_fibonacci([1, 1].into_iter()));
+        assert!(is_fibonacci([1].into_iter()));
+        assert!(is_fibonacci([].into_iter()));
 
-        assert_eq!(is_fibonacci([1, 1, 2, 2, 3, 3].into_iter()), false);
-        assert_eq!(is_fibonacci([0, 0, 0, 0, 1].into_iter()), false);
-        assert_eq!(is_fibonacci([1, 1, 1, 1].into_iter()), false);
-        assert_eq!(is_fibonacci([4, 3, 2, 1].into_iter()), false);
+        assert!(!is_fibonacci([1, 1, 2, 2, 3, 3].into_iter()));
+        assert!(!is_fibonacci([0, 0, 0, 0, 1].into_iter()));
+        assert!(!is_fibonacci([1, 1, 1, 1].into_iter()));
+        assert!(!is_fibonacci([4, 3, 2, 1].into_iter()));
     }
 
     #[test]
@@ -98,7 +98,7 @@ mod test {
                 vec![6, 9, 1, 14, 0, 4, 8, 7, 11, 2, 10, 3, 13, 12, 5].into_iter(),
                 5
             ),
-            ((0 + 1 + 2 + 3 + 4) as f64 / 5.0)
+            ((1 + 2 + 3 + 4) as f64 / 5.0)
         );
     }
 
diff --git a/src/bin/par_iter.rs b/src/bin/par_iter.rs
index 8dca66f..ba4989f 100644
--- a/src/bin/par_iter.rs
+++ b/src/bin/par_iter.rs
@@ -6,7 +6,6 @@ const SIZE: usize = 100_000_000;
 
 fn sequential() {
     let _v = (0..SIZE)
-        .into_iter()
         .filter_map(|x| if x % 2 == 0 { Some(x * 3) } else { None })
         .collect::<Vec<_>>();
 }
diff --git a/src/lib.rs b/src/lib.rs
index 9451db6..7c36a8a 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -13,7 +13,6 @@
 #![deny(pointer_structural_match)]
 #![deny(rust_2018_idioms)]
 #![deny(trivial_numeric_casts)]
-#![deny(unaligned_references)]
 // #![deny(unused_crate_dependencies)] // TODO: uncomment
 #![deny(unused_extern_crates)]
 #![deny(unused_import_braces)]