diff --git a/src/loops.rs b/src/loops.rs
index 36bab550b67..5f18439eafe 100644
--- a/src/loops.rs
+++ b/src/loops.rs
@@ -1,10 +1,9 @@
 use rustc::lint::*;
 use syntax::ast::*;
 use syntax::visit::{Visitor, walk_expr};
-use rustc::middle::ty;
 use std::collections::HashSet;
 
-use utils::{snippet, span_lint, get_parent_expr, match_def_path};
+use utils::{snippet, span_lint, get_parent_expr, match_trait_method};
 
 declare_lint!{ pub NEEDLESS_RANGE_LOOP, Warn,
                "for-looping over a range of indices where an iterator over items would do" }
@@ -68,16 +67,10 @@ impl LintPass for LoopsPass {
                             object, object));
                     // check for looping over Iterator::next() which is not what you want
                     } else if method_name == "next" {
-                        let method_call = ty::MethodCall::expr(arg.id);
-                        let trt_id = cx.tcx.tables
-                                           .borrow().method_map.get(&method_call)
-                                           .and_then(|callee| cx.tcx.trait_of_item(callee.def_id));
-                        if let Some(trt_id) = trt_id {
-                            if match_def_path(cx, trt_id, &["core", "iter", "Iterator"]) {
-                                span_lint(cx, ITER_NEXT_LOOP, expr.span,
-                                          "you are iterating over `Iterator::next()` which is an Option; \
-                                           this will compile but is probably not what you want");
-                            }
+                        if match_trait_method(cx, arg, &["core", "iter", "Iterator"]) {
+                            span_lint(cx, ITER_NEXT_LOOP, expr.span,
+                                      "you are iterating over `Iterator::next()` which is an Option; \
+                                       this will compile but is probably not what you want");
                         }
                     }
                 }
diff --git a/src/ranges.rs b/src/ranges.rs
index d1a0a7e702e..914b4daa6be 100644
--- a/src/ranges.rs
+++ b/src/ranges.rs
@@ -20,7 +20,7 @@ impl LintPass for StepByZero {
         if let ExprMethodCall(Spanned { node: ref ident, .. }, _,
                               ref args) = expr.node {
             // Only warn on literal ranges.
-            if ident.name.as_str() == "step_by" && args.len() == 2 &&
+            if ident.name == "step_by" && args.len() == 2 &&
                 is_range(cx, &args[0]) && is_lit_zero(&args[1]) {
                 cx.span_lint(RANGE_STEP_BY_ZERO, expr.span,
                              "Range::step_by(0) produces an infinite iterator. \
diff --git a/src/utils.rs b/src/utils.rs
index 4fd36fb91d4..5e7c63e85d9 100644
--- a/src/utils.rs
+++ b/src/utils.rs
@@ -56,6 +56,19 @@ pub fn match_type(cx: &Context, ty: ty::Ty, path: &[&str]) -> bool {
     }
 }
 
+/// check if method call given in "expr" belongs to given trait
+pub fn match_trait_method(cx: &Context, expr: &Expr, path: &[&str]) -> bool {
+    let method_call = ty::MethodCall::expr(expr.id);
+    let trt_id = cx.tcx.tables
+                       .borrow().method_map.get(&method_call)
+                       .and_then(|callee| cx.tcx.trait_of_item(callee.def_id));
+    if let Some(trt_id) = trt_id {
+        match_def_path(cx, trt_id, path)
+    } else {
+        false
+    }
+}
+
 /// match a Path against a slice of segment string literals, e.g.
 /// `match_path(path, &["std", "rt", "begin_unwind"])`
 pub fn match_path(path: &Path, segments: &[&str]) -> bool {