diff --git a/src/strings.rs b/src/strings.rs
index 60ea23556ac..47af63e6dea 100644
--- a/src/strings.rs
+++ b/src/strings.rs
@@ -18,9 +18,9 @@ declare_lint! {
 }
 
 declare_lint! {
-	pub STRING_ADD,
-	Allow,
-	"Warn on `x + ..` where x is a `String`"
+    pub STRING_ADD,
+    Allow,
+    "Warn on `x + ..` where x is a `String`"
 }
 
 #[derive(Copy, Clone)]
@@ -32,26 +32,26 @@ impl LintPass for StringAdd {
     }
 
     fn check_expr(&mut self, cx: &Context, e: &Expr) {
-		if let &ExprBinary(Spanned{ node: BiAdd, .. }, ref left, _) = &e.node {
-			if is_string(cx, left) {
-				if let Allow = cx.current_level(STRING_ADD_ASSIGN) {
-					// the string_add_assign is allow, so no duplicates
-				} else {
-					let parent = get_parent_expr(cx, e);
-					if let Some(ref p) = parent {
-						if let &ExprAssign(ref target, _) = &p.node {
-							// avoid duplicate matches
-							if is_exp_equal(target, left) { return; }
-						}
-					}
-				}
-				//TODO check for duplicates
-				 span_lint(cx, STRING_ADD, e.span,
-						"you add something to a string. \
-						Consider using `String::push_str()` instead.")
-			}
-		}
-	}
+        if let &ExprBinary(Spanned{ node: BiAdd, .. }, ref left, _) = &e.node {
+            if is_string(cx, left) {
+                if let Allow = cx.current_level(STRING_ADD_ASSIGN) {
+                    // the string_add_assign is allow, so no duplicates
+                } else {
+                    let parent = get_parent_expr(cx, e);
+                    if let Some(ref p) = parent {
+                        if let &ExprAssign(ref target, _) = &p.node {
+                            // avoid duplicate matches
+                            if is_exp_equal(target, left) { return; }
+                        }
+                    }
+                }
+                //TODO check for duplicates
+                 span_lint(cx, STRING_ADD, e.span,
+                        "you add something to a string. \
+                        Consider using `String::push_str()` instead.")
+            }
+        }
+    }
 }
             
 
@@ -75,7 +75,7 @@ impl LintPass for StringAddAssign {
 }
 
 fn is_string(cx: &Context, e: &Expr) -> bool {
-	let ty = walk_ptrs_ty(cx.tcx.expr_ty(e));
+    let ty = walk_ptrs_ty(cx.tcx.expr_ty(e));
     if let TyStruct(did, _) = ty.sty {
         match_def_path(cx, did.did, &["collections", "string", "String"])
     } else { false }