--- a/gfx/wr/peek-poke/tests/max_size.rs
+++ b/gfx/wr/peek-poke/tests/max_size.rs
@@ -47,17 +47,17 @@ fn test_option() {
 fn test_fixed_size_array() {
     assert_eq!(<[u32; 32]>::max_size(), 32 * size_of::<u32>());
     assert_eq!(<[u64; 8]>::max_size(), 8 * size_of::<u64>());
     assert_eq!(<[u8; 19]>::max_size(), 19 * size_of::<u8>());
 }
 
 #[test]
 fn test_tuple() {
-    assert_eq!(<(isize)>::max_size(), size_of::<isize>());
+    assert_eq!(<(isize, )>::max_size(), size_of::<isize>());
     assert_eq!(<(isize, isize, isize)>::max_size(), 3 * size_of::<isize>());
     assert_eq!(<(isize, ())>::max_size(), size_of::<isize>());
 }
 
 #[test]
 fn test_basic_struct() {
     #[derive(Debug, PeekPoke)]
     struct Bar {