diff --git a/src/comp/middle/trans.rs b/src/comp/middle/trans.rs
index bc43185a799..aede3110fe0 100644
--- a/src/comp/middle/trans.rs
+++ b/src/comp/middle/trans.rs
@@ -1789,7 +1789,6 @@ fn variant_types(@crate_ctxt cx, &ast.variant v) -> vec[@ty.t] {
             }
         }
         case (ty.ty_tag(_, _)) { /* nothing */ }
-        case (_) { fail; }
     }
     ret tys;
 }
@@ -2002,7 +2001,6 @@ fn iter_boxpp(@block_ctxt cx,
                                 j += 1;
                             }
                         }
-                        case (_) { fail; }
                     }
 
                     variant_cx.build.Br(next_cx.llbb);
@@ -2169,7 +2167,6 @@ fn iter_sequence_body(@block_ctxt cx,
             auto et = plain_ty(ty.ty_machine(common.ty_u8));
             ret iter_sequence_body(cx, v, et, f, true);
         }
-        case (_) { fail; }
     }
     cx.fcx.ccx.sess.bug("bad type in trans.iter_sequence");
     fail;
diff --git a/src/comp/middle/typeck.rs b/src/comp/middle/typeck.rs
index c849483e8ad..75d6a8fff61 100644
--- a/src/comp/middle/typeck.rs
+++ b/src/comp/middle/typeck.rs
@@ -1861,9 +1861,6 @@ fn check_assignment(&@fn_ctxt fcx, @ast.expr lhs, @ast.expr rhs)
                 case (ty.ty_chan(?it)) {
                     item_t = it;
                 }
-                case (_) {
-                    fail;
-                }
             }
             auto rhs_1 = demand_expr(fcx, item_t, rhs_0);
 
@@ -1884,9 +1881,6 @@ fn check_assignment(&@fn_ctxt fcx, @ast.expr lhs, @ast.expr rhs)
                 case (ty.ty_port(?it)) {
                     item_t = it;
                 }
-                case (_) {
-                    fail;
-                }
             }
             auto lhs_1 = demand_expr(fcx, item_t, lhs_0);
 
diff --git a/src/lib/deque.rs b/src/lib/deque.rs
index 776f82e99fe..704e6749300 100644
--- a/src/lib/deque.rs
+++ b/src/lib/deque.rs
@@ -47,7 +47,6 @@ fn fill[T](uint i, uint nelts, uint lo,
     fn get[T](vec[cell[T]] elts, uint i) -> T {
         alt (elts.(i)) {
             case (option.some[T](?t)) { ret t; }
-            case (_) { fail; }
         }
         fail;   // FIXME: remove me when exhaustiveness checking works
     }
diff --git a/src/lib/map.rs b/src/lib/map.rs
index f22faaca719..d8e24314086 100644
--- a/src/lib/map.rs
+++ b/src/lib/map.rs
@@ -176,7 +176,6 @@ fn contains_key(&K key) -> bool {
             fn get(&K key) -> V {
                 alt (find_common[K, V](hasher, eqer, bkts, nbkts, key)) {
                     case (option.some[V](?val)) { ret val; }
-                    case (_) { fail; }
                 }
                 fail;   // FIXME: remove me when exhaustiveness checking works
             }