diff --git a/src/comp/middle/typeck.rs b/src/comp/middle/typeck.rs
index 6fbe6493061e..41a2daf0e448 100644
--- a/src/comp/middle/typeck.rs
+++ b/src/comp/middle/typeck.rs
@@ -229,11 +229,6 @@ fn type_is_scalar(&@fn_ctxt fcx, &span sp, ty::t typ) -> bool {
     ret ty::type_is_scalar(fcx.ccx.tcx, typ_s);
 }
 
-fn type_is_str(&@fn_ctxt fcx, &span sp, ty::t typ) -> bool {
-    auto typ_s = structurally_resolved_type(fcx, sp, typ);
-    ret ty::type_is_str(fcx.ccx.tcx, typ_s);    
-}
-
 
 // Parses the programmer's textual representation of a type into our internal
 // notion of a type. `getter` is a function that returns the type
@@ -1667,12 +1662,7 @@ fn check_expr(&@fn_ctxt fcx, &@ast::expr expr) {
                     check_expr(fcx, e);
                     auto tcx = fcx.ccx.tcx;
                     auto ety = expr_ty(tcx, e);
-                    if (!type_is_str(fcx, e.span, ety)) {
-                        tcx.sess.span_fatal(e.span,
-                                            #fmt("mismatched types: expected \
-                                                  str, found %s",
-                                                 ty_to_str(tcx, ety)));
-                    }
+                    demand::simple(fcx, e.span, ty::mk_str(tcx), ety);
                 }
             }
             write::bot_ty(fcx.ccx.tcx, id);