diff --git a/src/comp/middle/alias.rs b/src/comp/middle/alias.rs
index 4e86427194b..a5534b8d597 100644
--- a/src/comp/middle/alias.rs
+++ b/src/comp/middle/alias.rs
@@ -103,11 +103,11 @@ fn visit_expr(&@ctx cx, &@ast::expr ex, &scope sc, &vt[scope] v) {
                 case (_) { }
             }
         }
-        ast::expr_for_each(?decl, ?call, ?block) {
-            check_for_each(*cx, decl, call, block, sc, v);
+        ast::expr_for_each(?decl, ?call, ?blk) {
+            check_for_each(*cx, decl, call, blk, sc, v);
         }
-        ast::expr_for(?decl, ?seq, ?block) {
-            check_for(*cx, decl, seq, block, sc, v);
+        ast::expr_for(?decl, ?seq, ?blk) {
+            check_for(*cx, decl, seq, blk, sc, v);
         }
         ast::expr_path(?pt) {
             check_var(*cx, ex, pt, ex.id, false, sc);
@@ -326,7 +326,7 @@ fn arm_defnums(&ast::arm arm) -> node_id[] {
 }
 
 fn check_for_each(&ctx cx, &@ast::local local, &@ast::expr call,
-                  &ast::block block, &scope sc, &vt[scope] v) {
+                  &ast::block blk, &scope sc, &vt[scope] v) {
     visit::visit_expr(call, sc, v);
     alt (call.node) {
         case (ast::expr_call(?f, ?args)) {
@@ -339,12 +339,12 @@ fn check_for_each(&ctx cx, &@ast::local local, &@ast::expr call,
                      tys=data.unsafe_ts,
                      depends_on=deps(sc, data.root_vars),
                      mutable ok=valid);
-            visit::visit_block(block, @(*sc + ~[new_sc]), v);
+            visit::visit_block(blk, @(*sc + ~[new_sc]), v);
         }
     }
 }
 
-fn check_for(&ctx cx, &@ast::local local, &@ast::expr seq, &ast::block block,
+fn check_for(&ctx cx, &@ast::local local, &@ast::expr seq, &ast::block blk,
              &scope sc, &vt[scope] v) {
     visit::visit_expr(seq, sc, v);
     auto defnum = local.node.id;
@@ -374,7 +374,7 @@ fn check_for(&ctx cx, &@ast::local local, &@ast::expr seq, &ast::block block,
              tys=unsafe,
              depends_on=deps(sc, root_def),
              mutable ok=valid);
-    visit::visit_block(block, @(*sc + ~[new_sc]), v);
+    visit::visit_block(blk, @(*sc + ~[new_sc]), v);
 }
 
 fn check_var(&ctx cx, &@ast::expr ex, &ast::path p, ast::node_id id,
diff --git a/src/comp/middle/trans_dps.rs b/src/comp/middle/trans_dps.rs
index 193155d259c..68f4c7eb609 100644
--- a/src/comp/middle/trans_dps.rs
+++ b/src/comp/middle/trans_dps.rs
@@ -446,14 +446,14 @@ fn trans_recv(&@block_ctxt bcx, &dest dest, &@ast::expr expr) -> @block_ctxt {
     ret bcx;    // TODO
 }
 
-fn trans_block(&@block_ctxt cx, &dest dest, &ast::block block)
+fn trans_block(&@block_ctxt cx, &dest dest, &ast::block blk)
         -> @block_ctxt {
     auto bcx = cx;
-    for each (@ast::local local in trans::block_locals(block)) {
+    for each (@ast::local local in trans::block_locals(blk)) {
         bcx = trans::alloc_local(bcx, local).bcx;
     }
 
-    for (@ast::stmt stmt in block.node.stmts) {
+    for (@ast::stmt stmt in blk.node.stmts) {
         bcx = trans_stmt(bcx, stmt);
 
         // If we hit a terminator, control won't go any further so
@@ -461,7 +461,7 @@ fn trans_block(&@block_ctxt cx, &dest dest, &ast::block block)
         if trans::is_terminated(bcx) { ret bcx; }
     }
 
-    alt (block.node.expr) {
+    alt (blk.node.expr) {
       some(?e) { bcx = trans_expr(bcx, dest, e); }
       none { /* no-op */ }
     }
diff --git a/src/comp/middle/typeck.rs b/src/comp/middle/typeck.rs
index 584ac7d44fd..5ddd76337d2 100644
--- a/src/comp/middle/typeck.rs
+++ b/src/comp/middle/typeck.rs
@@ -1147,7 +1147,7 @@ mod writeback {
     }
     fn keep_going(@wb_ctxt wbcx) -> bool { !wbcx.ignore && wbcx.success }
 
-    fn resolve_type_vars_in_block(&@fn_ctxt fcx, &ast::block block) -> bool {
+    fn resolve_type_vars_in_block(&@fn_ctxt fcx, &ast::block blk) -> bool {
         auto wbcx = @rec(fcx = fcx,
                          mutable ignore = false,
                          mutable success = true);
@@ -1163,7 +1163,7 @@ mod writeback {
                 visit_pat_pre=bind visit_pat_pre(wbcx, _),
                 visit_local_pre=bind visit_local_pre(wbcx, _)
                 with walk::default_visitor());
-        walk::walk_block(visit, block);
+        walk::walk_block(visit, blk);
         ret wbcx.success;
     }
 }
@@ -2598,14 +2598,14 @@ fn check_stmt(&@fn_ctxt fcx, &@ast::stmt stmt) {
     write::nil_ty(fcx.ccx.tcx, node_id);
 }
 
-fn check_block(&@fn_ctxt fcx, &ast::block block) {
-    for (@ast::stmt s in block.node.stmts) { check_stmt(fcx, s); }
-    alt (block.node.expr) {
-        case (none) { write::nil_ty(fcx.ccx.tcx, block.node.id); }
+fn check_block(&@fn_ctxt fcx, &ast::block blk) {
+    for (@ast::stmt s in blk.node.stmts) { check_stmt(fcx, s); }
+    alt (blk.node.expr) {
+        case (none) { write::nil_ty(fcx.ccx.tcx, blk.node.id); }
         case (some(?e)) {
             check_expr(fcx, e);
             auto ety = expr_ty(fcx.ccx.tcx, e);
-            write::ty_only_fixup(fcx, block.node.id, ety);
+            write::ty_only_fixup(fcx, blk.node.id, ety);
         }
     }
 }
diff --git a/src/comp/syntax/fold.rs b/src/comp/syntax/fold.rs
index f29649085b4..ea41aecbadc 100644
--- a/src/comp/syntax/fold.rs
+++ b/src/comp/syntax/fold.rs
@@ -138,8 +138,8 @@ fn fold_mac_(&mac m, ast_fold fld) -> mac {
                 case (mac_embed_type(?ty)) {
                     mac_embed_type(fld.fold_ty(ty))
                 }
-                case (mac_embed_block(?block)) {
-                    mac_embed_block(fld.fold_block(block))
+                case (mac_embed_block(?blk)) {
+                    mac_embed_block(fld.fold_block(blk))
                 }
                 case (mac_ellipsis) { mac_ellipsis }
             },
@@ -388,16 +388,16 @@ fn noop_fold_expr(&expr_ e, ast_fold fld) -> expr_ {
         case (expr_while(?cond, ?body)) {
             expr_while(fld.fold_expr(cond), fld.fold_block(body))
                 }
-        case (expr_for(?decl, ?expr, ?block)) {
+        case (expr_for(?decl, ?expr, ?blk)) {
             expr_for(fld.fold_local(decl), fld.fold_expr(expr),
-                     fld.fold_block(block))
+                     fld.fold_block(blk))
                 }
-        case (expr_for_each(?decl, ?expr, ?block)) {
+        case (expr_for_each(?decl, ?expr, ?blk)) {
             expr_for_each(fld.fold_local(decl), fld.fold_expr(expr),
-                          fld.fold_block(block))
+                          fld.fold_block(blk))
                 }
-        case (expr_do_while(?block, ?expr)) {
-            expr_do_while(fld.fold_block(block), fld.fold_expr(expr))
+        case (expr_do_while(?blk, ?expr)) {
+            expr_do_while(fld.fold_block(blk), fld.fold_expr(expr))
                 }
         case (expr_alt(?expr, ?arms)) {
             expr_alt(fld.fold_expr(expr), ivec::map(fld.fold_arm, arms))
@@ -405,8 +405,8 @@ fn noop_fold_expr(&expr_ e, ast_fold fld) -> expr_ {
         case (expr_fn(?f)) {
             expr_fn(fld.fold_fn(f))
                 }
-        case (expr_block(?block)) {
-            expr_block(fld.fold_block(block))
+        case (expr_block(?blk)) {
+            expr_block(fld.fold_block(blk))
                 }
         case (expr_move(?el, ?er)) {
             expr_move(fld.fold_expr(el), fld.fold_expr(er))
diff --git a/src/comp/syntax/parse/parser.rs b/src/comp/syntax/parse/parser.rs
index 221c97b8dac..a91a95dd77f 100644
--- a/src/comp/syntax/parse/parser.rs
+++ b/src/comp/syntax/parse/parser.rs
@@ -174,6 +174,7 @@ fn bad_expr_word_table() -> hashmap[str, ()] {
     words.insert("fn", ());
     words.insert("pred", ());
     words.insert("iter", ());
+    words.insert("block", ());
     words.insert("import", ());
     words.insert("export", ());
     words.insert("let", ());
@@ -1407,8 +1408,8 @@ fn parse_alt_expr(&parser p) -> @ast::expr {
         if (p.peek() == token::LPAREN) { parens = true; p.bump(); }
         auto pats = parse_pats(p);
         if (parens) { expect(p, token::RPAREN); }
-        auto block = parse_block(p);
-        arms += ~[rec(pats=pats, block=block)];
+        auto blk = parse_block(p);
+        arms += ~[rec(pats=pats, block=blk)];
     }
     auto hi = p.get_hi_pos();
     p.bump();
diff --git a/src/comp/syntax/print/pprust.rs b/src/comp/syntax/print/pprust.rs
index 4dc65d112bc..b3a915070a0 100644
--- a/src/comp/syntax/print/pprust.rs
+++ b/src/comp/syntax/print/pprust.rs
@@ -601,7 +601,7 @@ fn print_possibly_embedded_block(&ps s, &ast::block blk, bool embedded,
     s.ann.post(ann_node);
 }
 
-fn print_if(&ps s, &@ast::expr test, &ast::block block,
+fn print_if(&ps s, &@ast::expr test, &ast::block blk,
             &option::t[@ast::expr] elseopt, bool chk) {
     head(s, "if");
     if (chk) {
@@ -609,7 +609,7 @@ fn print_if(&ps s, &@ast::expr test, &ast::block block,
     }
     print_expr(s, test);
     space(s.s);
-    print_block(s, block);
+    print_block(s, blk);
     fn do_else(&ps s, option::t[@ast::expr] els) {
         alt (els) {
             case (some(?_else)) {
@@ -773,11 +773,11 @@ fn print_expr(&ps s, &@ast::expr expr) {
             word_space(s, "as");
             print_type(s, *ty);
         }
-        case (ast::expr_if(?test, ?block, ?elseopt)) {
-            print_if(s, test, block, elseopt, false);
+        case (ast::expr_if(?test, ?blk, ?elseopt)) {
+            print_if(s, test, blk, elseopt, false);
         }
-        case (ast::expr_if_check(?test, ?block, ?elseopt)) {
-            print_if(s, test, block, elseopt, true);
+        case (ast::expr_if_check(?test, ?blk, ?elseopt)) {
+            print_if(s, test, blk, elseopt, true);
         }
         case (ast::expr_ternary(?test, ?then, ?els)) {
             print_expr(s, test);
@@ -788,13 +788,13 @@ fn print_expr(&ps s, &@ast::expr expr) {
             word_space(s, ":");
             print_expr(s, els);
         }
-        case (ast::expr_while(?test, ?block)) {
+        case (ast::expr_while(?test, ?blk)) {
             head(s, "while");
             print_expr(s, test);
             space(s.s);
-            print_block(s, block);
+            print_block(s, blk);
         }
-        case (ast::expr_for(?decl, ?expr, ?block)) {
+        case (ast::expr_for(?decl, ?expr, ?blk)) {
             head(s, "for");
             popen(s);
             print_for_decl(s, decl);
@@ -803,9 +803,9 @@ fn print_expr(&ps s, &@ast::expr expr) {
             print_expr(s, expr);
             pclose(s);
             space(s.s);
-            print_block(s, block);
+            print_block(s, blk);
         }
-        case (ast::expr_for_each(?decl, ?expr, ?block)) {
+        case (ast::expr_for_each(?decl, ?expr, ?blk)) {
             head(s, "for each");
             popen(s);
             print_for_decl(s, decl);
@@ -814,12 +814,12 @@ fn print_expr(&ps s, &@ast::expr expr) {
             print_expr(s, expr);
             pclose(s);
             space(s.s);
-            print_block(s, block);
+            print_block(s, blk);
         }
-        case (ast::expr_do_while(?block, ?expr)) {
+        case (ast::expr_do_while(?blk, ?expr)) {
             head(s, "do");
             space(s.s);
-            print_block(s, block);
+            print_block(s, blk);
             space(s.s);
             word_space(s, "while");
             print_expr(s, expr);
@@ -853,14 +853,14 @@ fn print_expr(&ps s, &@ast::expr expr) {
             space(s.s);
             print_block(s, f.body);
         }
-        case (ast::expr_block(?block)) {
+        case (ast::expr_block(?blk)) {
             // containing cbox, will be closed by print-block at }
 
             cbox(s, indent_unit);
             // head-box, will be closed by print-block after {
 
             ibox(s, 0u);
-            print_block(s, block);
+            print_block(s, blk);
         }
         case (ast::expr_move(?lhs, ?rhs)) {
             print_expr(s, lhs);