diff --git a/.circleci/config.yml b/.circleci/config.yml
index 9062b0de..30497ab4 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -99,7 +99,7 @@ jobs:
       - run:
           name: Install rustfmt-nightly
           # this is not cheap, but I did not find a better way
-          command: cargo install rustfmt-nightly --force
+          command: cargo install rustfmt-nightly --version=0.8.3 --force
       - run:
           name: Run cargo fmt
           command: cargo fmt -- --check
diff --git a/src/drgraph.rs b/src/drgraph.rs
index 6056bdef..bb66a7fe 100644
--- a/src/drgraph.rs
+++ b/src/drgraph.rs
@@ -91,18 +91,19 @@ impl MerkleProof {
             return false;
         }
 
-        self.root() == (0..self.path.len()).fold(self.leaf, |h, i| {
-            a.reset();
-            let is_right = self.path[i].1;
-
-            let (left, right) = if is_right {
-                (self.path[i].0, h)
-            } else {
-                (h, self.path[i].0)
-            };
-
-            a.node(left, right, i)
-        })
+        self.root()
+            == (0..self.path.len()).fold(self.leaf, |h, i| {
+                a.reset();
+                let is_right = self.path[i].1;
+
+                let (left, right) = if is_right {
+                    (self.path[i].0, h)
+                } else {
+                    (h, self.path[i].0)
+                };
+
+                a.node(left, right, i)
+            })
     }
 
     /// Validates that the data hashes to the leaf of the merkle path.
diff --git a/src/example_helper.rs b/src/example_helper.rs
index b41dc96d..c7f84a94 100644
--- a/src/example_helper.rs
+++ b/src/example_helper.rs
@@ -26,7 +26,8 @@ fn prettyb(num: usize) -> String {
     );
     let pretty_bytes = format!("{:.2}", num / delimiter.powi(exponent))
         .parse::<f64>()
-        .unwrap() * 1_f64;
+        .unwrap()
+        * 1_f64;
     let unit = units[exponent as usize];
     format!("{}{} {}", negative, pretty_bytes, unit)
 }
diff --git a/src/zigzag_graph.rs b/src/zigzag_graph.rs
index 3cb7bcb5..ab05de77 100644
--- a/src/zigzag_graph.rs
+++ b/src/zigzag_graph.rs
@@ -14,11 +14,7 @@ where
     pub reversed: bool,
 }
 
-impl<'a, G> Layerable for ZigZagGraph<G>
-where
-    G: ZigZag,
-{
-}
+impl<'a, G> Layerable for ZigZagGraph<G> where G: ZigZag {}
 
 impl<G: Graph> ZigZagGraph<G> {
     fn new<'b>(nodes: usize, base_degree: usize, expansion_degree: usize) -> Self {