diff --git a/cranelift/src/wasm.rs b/cranelift/src/wasm.rs
index 3a972e9716..c54cfa85d0 100644
--- a/cranelift/src/wasm.rs
+++ b/cranelift/src/wasm.rs
@@ -57,7 +57,7 @@ pub fn run(
     flag_optimize: bool,
     flag_check: bool,
 ) -> Result<(), String> {
-    for filename in files.iter() {
+    for filename in files {
         let path = Path::new(&filename);
         let name = String::from(path.as_os_str().to_string_lossy());
         match handle_module(
@@ -148,7 +148,7 @@ fn handle_module(
         terminal.fg(term::color::MAGENTA).unwrap();
         vprint!(flag_verbose, "Checking...   ");
         terminal.reset().unwrap();
-        for func in translation.functions.iter() {
+        for func in &translation.functions {
             let il = match *func {
                 FunctionTranslation::Import() => continue,
                 FunctionTranslation::Code { ref il, .. } => il.clone(),
@@ -166,7 +166,7 @@ fn handle_module(
         terminal.fg(term::color::MAGENTA).unwrap();
         vprint!(flag_verbose, "Optimizing... ");
         terminal.reset().unwrap();
-        for func in translation.functions.iter() {
+        for func in &translation.functions {
             let mut il = match *func {
                 FunctionTranslation::Import() => continue,
                 FunctionTranslation::Code { ref il, .. } => il.clone(),
diff --git a/lib/cretonne/src/regalloc/liveness.rs b/lib/cretonne/src/regalloc/liveness.rs
index 72b3814770..2c3c430534 100644
--- a/lib/cretonne/src/regalloc/liveness.rs
+++ b/lib/cretonne/src/regalloc/liveness.rs
@@ -433,7 +433,7 @@ impl Liveness {
         assert!(self.ebb_args.is_empty());
 
         for ebb in func.layout.ebbs() {
-            for &arg in func.dfg.ebb_args(ebb).iter() {
+            for &arg in func.dfg.ebb_args(ebb) {
                 let affinity = self.ranges.get(arg).unwrap().affinity;
                 if affinity.is_none() {
                     continue;
diff --git a/lib/frontend/src/ssa.rs b/lib/frontend/src/ssa.rs
index 250d679983..ecfe57b234 100644
--- a/lib/frontend/src/ssa.rs
+++ b/lib/frontend/src/ssa.rs
@@ -421,7 +421,7 @@ where
         // `use_var`'s traversal won't revisit these predecesors.
         let mut preds = Vec::new();
         mem::swap(&mut preds, &mut self.predecessors_mut(dest_ebb));
-        for &(pred, last_inst) in preds.iter() {
+        for &(pred, last_inst) in &preds {
             // For each predecessor, we query what is the local SSA value corresponding
             // to var and we put it as an argument of the branch instruction.
             let (pred_val, mut local_side_effects) =
diff --git a/lib/wasm/tests/testsuite.rs b/lib/wasm/tests/testsuite.rs
index d4c51c6a90..cb56779b00 100644
--- a/lib/wasm/tests/testsuite.rs
+++ b/lib/wasm/tests/testsuite.rs
@@ -69,8 +69,8 @@ fn handle_module(path: PathBuf) -> Result<(), String> {
             }
         }
     };
-    for func in translation.functions.iter() {
-        let il = match *func {
+    for func in translation.functions {
+        let il = match func {
             FunctionTranslation::Import() => continue,
             FunctionTranslation::Code { ref il, .. } => il.clone(),
         };