diff --git a/mrbgems/mruby-compiler/core/codegen.c b/mrbgems/mruby-compiler/core/codegen.c
index 5cf56b643..7429b7e60 100644
--- a/mrbgems/mruby-compiler/core/codegen.c
+++ b/mrbgems/mruby-compiler/core/codegen.c
@@ -1376,7 +1376,7 @@ lambda_body(codegen_scope *s, node *tree, int blk)
     pa = node_len(tree->car->cdr->cdr->cdr->car);
     pargs = tree->car->cdr->cdr->cdr->car;
     /* keyword arguments */
-    ka = tail? node_len(tail->cdr->car) : 0;
+    ka = tail ? node_len(tail->cdr->car) : 0;
     /* keyword dictionary? */
     kd = tail && tail->cdr->cdr->car? 1 : 0;
     /* block argument? */
@@ -1388,16 +1388,16 @@ lambda_body(codegen_scope *s, node *tree, int blk)
     /* (23bits = 5:5:1:5:5:1:1) */
     a = MRB_ARGS_REQ(ma)
       | MRB_ARGS_OPT(oa)
-      | (ra? MRB_ARGS_REST() : 0)
+      | (ra ? MRB_ARGS_REST() : 0)
       | MRB_ARGS_POST(pa)
       | MRB_ARGS_KEY(ka, kd)
-      | (ba? MRB_ARGS_BLOCK() : 0);
+      | (ba ? MRB_ARGS_BLOCK() : 0);
     genop_W(s, OP_ENTER, a);
     /* (12bits = 5:1:5:1) */
     s->ainfo = (((ma+oa) & 0x3f) << 7)
       | ((ra & 0x1) << 6)
       | ((pa & 0x1f) << 1)
-      | ((ka | kd) ? 1 : 0);
+      | (ka || kd);
     /* generate jump table for optional arguments initializer */
     pos = new_label(s);
     for (i=0; i<oa; i++) {
@@ -1475,6 +1475,14 @@ lambda_body(codegen_scope *s, node *tree, int blk)
       if (tail->cdr->car && !kwrest) {
         genop_0(s, OP_KEYEND);
       }
+      if (ba) {
+        mrb_sym bparam = nsym(tail->cdr->cdr->cdr->car);
+        pos = ma+oa+ra+pa+(ka||kd);
+        if (bparam) {
+          int idx = lv_idx(s, bparam);
+          genop_2(s, OP_MOVE, idx, pos+1);
+        }
+      }
     }
 
     /* argument destructuring */
diff --git a/mrbgems/mruby-compiler/core/parse.y b/mrbgems/mruby-compiler/core/parse.y
index 843d3da43..415119287 100644
--- a/mrbgems/mruby-compiler/core/parse.y
+++ b/mrbgems/mruby-compiler/core/parse.y
@@ -334,12 +334,8 @@ local_add(parser_state *p, mrb_sym sym)
   }
 }
 
-static void
-local_add_blk(parser_state *p, mrb_sym blk)
-{
-  /* allocate register for block */
-  local_add_f(p, blk ? blk : 0);
-}
+/* allocate register for block */
+#define local_add_blk(p) local_add_f(p, 0)
 
 static void
 local_add_kw(parser_state *p, mrb_sym kwd)
@@ -865,7 +861,8 @@ new_args_tail(parser_state *p, node *kws, node *kwrest, mrb_sym blk)
     local_add_kw(p, (kwrest && kwrest->cdr)? sym(kwrest->cdr) : 0);
   }
 
-  local_add_blk(p, blk);
+  local_add_blk(p);
+  if (blk) local_add_f(p, blk);
 
   /* allocate register for keywords arguments */
   /* order is for Proc#parameters */
@@ -3096,7 +3093,7 @@ block_param     : f_arg ',' f_block_optarg ',' f_rest_arg opt_block_args_tail
 
 opt_block_param : none
                     {
-                      local_add_blk(p, 0);
+                      local_add_blk(p);
                       $$ = 0;
                     }
                 | block_param_def
@@ -3106,13 +3103,13 @@ opt_block_param : none
                     }
                 ;
 
-block_param_def : '|' {local_add_blk(p, 0);} opt_bv_decl '|'
+block_param_def : '|' {local_add_blk(p);} opt_bv_decl '|'
                     {
                       $$ = 0;
                     }
                 | tOROP
                     {
-                      local_add_blk(p, 0);
+                      local_add_blk(p);
                       $$ = 0;
                     }
                 | '|' block_param opt_bv_decl '|'
diff --git a/mrbgems/mruby-proc-ext/src/proc.c b/mrbgems/mruby-proc-ext/src/proc.c
index 8586abc77..bd2b20260 100644
--- a/mrbgems/mruby-proc-ext/src/proc.c
+++ b/mrbgems/mruby-proc-ext/src/proc.c
@@ -152,6 +152,9 @@ mrb_proc_parameters(mrb_state *mrb, mrb_value self)
         mrb_ary_push(mrb, a, mrb_symbol_value(irep->lv[i]));
       }
       if (p->name == MRB_SYM(block)) {
+        if (irep->lv[i+1]) {
+          mrb_ary_push(mrb, a, mrb_symbol_value(irep->lv[i+1]));
+        }
         block = a; continue;
       }
       if (p->name == MRB_SYM(keyrest)) {
diff --git a/mrbgems/mruby-proc-ext/test/proc.rb b/mrbgems/mruby-proc-ext/test/proc.rb
index 13e7058f9..7a105323a 100644
--- a/mrbgems/mruby-proc-ext/test/proc.rb
+++ b/mrbgems/mruby-proc-ext/test/proc.rb
@@ -33,11 +33,6 @@ assert('Proc#inspect') do
   assert_match "#<Proc:0x* #{file}:#{line}>", ins
 end
 
-assert('Proc#parameters') do
-  parameters = Proc.new{|x,y=42,*other|}.parameters
-  assert_equal [[:opt, :x], [:opt, :y], [:rest, :other]], parameters
-end
-
 assert('Proc#lambda?') do
   assert_true lambda{}.lambda?
   assert_true !Proc.new{}.lambda?
@@ -80,6 +75,7 @@ assert('Proc#parameters') do
   assert_equal([[:req, :a]], ->(a){}.parameters)
   assert_equal([[:rest, :*]], lambda { |*| }.parameters)
   assert_equal([[:rest, :a]], Proc.new {|*a|}.parameters)
+  assert_equal([[:opt, :x], [:opt, :y], [:rest, :other]], Proc.new{|x,y=42,*other|}.parameters)
   assert_equal([[:opt, :a], [:opt, :b], [:opt, :c], [:opt, :d], [:rest, :e], [:opt, :f], [:opt, :g], [:block, :h]], Proc.new {|a,b,c=:c,d=:d,*e,f,g,&h|}.parameters)
   assert_equal([[:req, :a], [:req, :b], [:opt, :c], [:opt, :d], [:rest, :e], [:req, :f], [:req, :g], [:block, :h]], lambda {|a,b,c=:c,d=:d,*e,f,g,&h|}.parameters)
 end