diff --git a/clippy_lints/src/new_without_default.rs b/clippy_lints/src/new_without_default.rs
index 2fc6695fa8b..e28d077f999 100644
--- a/clippy_lints/src/new_without_default.rs
+++ b/clippy_lints/src/new_without_default.rs
@@ -108,13 +108,12 @@ fn check_fn(
                 // can't be implemented by default
                 return;
             }
-            //TODO: There is no sig.generics anymore and I don't know how to fix this.
-            //if !sig.generics.ty_params.is_empty() {
-            //    // when the result of `new()` depends on a type parameter we should not require
-            //    // an
-            //    // impl of `Default`
-            //    return;
-            //}
+            if !cx.generics.expect("method must have generics").ty_params.is_empty() {
+               // when the result of `new()` depends on a type parameter we should not require
+               // an
+               // impl of `Default`
+               return;
+            }
             if decl.inputs.is_empty() && name == "new" && cx.access_levels.is_reachable(id) {
                 let self_ty = cx.tcx
                     .type_of(cx.tcx.hir.local_def_id(cx.tcx.hir.get_parent(id)));
diff --git a/tests/ui/mut_mut.stderr b/tests/ui/mut_mut.stderr
index 31f9178aa27..8bfc2fc8a5c 100644
--- a/tests/ui/mut_mut.stderr
+++ b/tests/ui/mut_mut.stderr
@@ -39,12 +39,6 @@ error: generally you want to avoid `&mut &mut _` if possible
 30 |         let y : &mut &mut u32 = &mut &mut 2;
    |                 ^^^^^^^^^^^^^
 
-error: generally you want to avoid `&mut &mut _` if possible
-  --> $DIR/mut_mut.rs:30:17
-   |
-30 |         let y : &mut &mut u32 = &mut &mut 2;
-   |                 ^^^^^^^^^^^^^
-
 error: generally you want to avoid `&mut &mut _` if possible
   --> $DIR/mut_mut.rs:35:38
    |
@@ -63,21 +57,3 @@ error: generally you want to avoid `&mut &mut _` if possible
 35 |         let y : &mut &mut &mut u32 = &mut &mut &mut 2;
    |                      ^^^^^^^^^^^^^
 
-error: generally you want to avoid `&mut &mut _` if possible
-  --> $DIR/mut_mut.rs:35:17
-   |
-35 |         let y : &mut &mut &mut u32 = &mut &mut &mut 2;
-   |                 ^^^^^^^^^^^^^^^^^^
-
-error: generally you want to avoid `&mut &mut _` if possible
-  --> $DIR/mut_mut.rs:35:22
-   |
-35 |         let y : &mut &mut &mut u32 = &mut &mut &mut 2;
-   |                      ^^^^^^^^^^^^^
-
-error: generally you want to avoid `&mut &mut _` if possible
-  --> $DIR/mut_mut.rs:35:22
-   |
-35 |         let y : &mut &mut &mut u32 = &mut &mut &mut 2;
-   |                      ^^^^^^^^^^^^^
-