diff --git a/src/librustc_metadata/encoder.rs b/src/librustc_metadata/encoder.rs
index 212de375a3f91..b65e9a715faca 100644
--- a/src/librustc_metadata/encoder.rs
+++ b/src/librustc_metadata/encoder.rs
@@ -930,7 +930,7 @@ impl<'a, 'b: 'a, 'tcx: 'b> IsolatedEncoder<'a, 'b, 'tcx> {
             } else if let hir::ImplItemKind::Method(ref sig, _) = ast_item.node {
                 let generics = self.tcx.generics_of(def_id);
                 let types = generics.parent_types as usize + generics.types.len();
-                let needs_inline = types > 0 || tcx.trans_fn_attrs(def_id).requests_inline() &&
+                let needs_inline = (types > 0 || tcx.trans_fn_attrs(def_id).requests_inline()) &&
                     !self.metadata_output_only();
                 let is_const_fn = sig.constness == hir::Constness::Const;
                 let always_encode_mir = self.tcx.sess.opts.debugging_opts.always_encode_mir;