diff --git a/src/Makefile b/src/Makefile
index 12b65246754..70b3ca0f53d 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -416,7 +416,6 @@ TEST_XFAILS_BOOT :=  $(TASK_XFAILS) \
                     test/run-pass/obj-as.rs \
                     test/run-pass/vec-slice.rs \
                     test/run-pass/fn-lval.rs \
-                    test/run-pass/generic-fn-box.rs \
                     test/run-pass/generic-recursive-tag.rs \
                     test/run-pass/generic-tup.rs \
                     test/run-pass/iter-ret.rs \
diff --git a/src/comp/middle/trans.rs b/src/comp/middle/trans.rs
index 72f1106b217..30f3cdc4495 100644
--- a/src/comp/middle/trans.rs
+++ b/src/comp/middle/trans.rs
@@ -3132,9 +3132,9 @@ fn trans_args(@block_ctxt cx,
             bcx = re.bcx;
         }
 
-        if (ty.count_ty_params(args.(i).ty) > 0u) {
-            auto lldestty = type_of(cx.fcx.ccx, args.(i).ty);
-            val = bcx.build.PointerCast(val, lldestty);
+        if (ty.type_has_dynamic_size(args.(i).ty)) {
+            val = bcx.build.PointerCast(val,
+                                        T_typaram_ptr(cx.fcx.ccx.tn));
         }
 
         llargs += val;
diff --git a/src/test/run-pass/generic-fn-box.rs b/src/test/run-pass/generic-fn-box.rs
deleted file mode 100644
index e821a784598..00000000000
--- a/src/test/run-pass/generic-fn-box.rs
+++ /dev/null
@@ -1,9 +0,0 @@
-fn f[T](@T x) -> @T {
-    ret x;
-}
-
-fn main() {
-    auto x = f(@3);
-    log *x;
-}
-