diff --git a/ChangeLog b/ChangeLog
index 9ff92025c1..bd1b860c53 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Sat Jul 30 12:10:51 2016  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* proc.c (passed_block): convert passed block symbol to proc.
+	  based on the patch by Daisuke Sato in [ruby-dev:49695].
+	  [Bug #12531]
+
 Sat Jul 30 10:58:49 2016  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* vm_insnhelper.c (vm_throw_start): check if the iseq is symbol
diff --git a/proc.c b/proc.c
index 018b6709d1..5387298692 100644
--- a/proc.c
+++ b/proc.c
@@ -809,6 +809,20 @@ check_argc(long argc)
 #define check_argc(argc) (argc)
 #endif
 
+static rb_block_t *
+passed_block(VALUE pass_procval)
+{
+    if (!NIL_P(pass_procval)) {
+	rb_proc_t *pass_proc;
+	if (SYMBOL_P(pass_procval)) {
+	    pass_procval = sym_proc_new(rb_cProc, pass_procval);
+	}
+	GetProcPtr(pass_procval, pass_proc);
+	return &pass_proc->block;
+    }
+    return 0;
+}
+
 VALUE
 rb_proc_call(VALUE self, VALUE args)
 {
@@ -829,12 +843,7 @@ rb_proc_call_with_block(VALUE self, int argc, const VALUE *argv, VALUE pass_proc
     rb_block_t *block = 0;
     GetProcPtr(self, proc);
 
-    if (!NIL_P(pass_procval)) {
-	rb_proc_t *pass_proc;
-	GetProcPtr(pass_procval, pass_proc);
-	block = &pass_proc->block;
-    }
-
+    block = passed_block(pass_procval);
     vret = rb_vm_invoke_proc(GET_THREAD(), proc, argc, argv, block);
     RB_GC_GUARD(self);
     RB_GC_GUARD(pass_procval);
@@ -1981,15 +1990,8 @@ rb_method_call_with_block(int argc, const VALUE *argv, VALUE method, VALUE pass_
     }
     if ((state = EXEC_TAG()) == 0) {
 	rb_thread_t *th = GET_THREAD();
-	rb_block_t *block = 0;
 
-	if (!NIL_P(pass_procval)) {
-	    rb_proc_t *pass_proc;
-	    GetProcPtr(pass_procval, pass_proc);
-	    block = &pass_proc->block;
-	}
-
-	th->passed_block = block;
+	th->passed_block = passed_block(pass_procval);
 	VAR_INITIALIZED(data);
 	result = rb_vm_call(th, data->recv, data->me->called_id, argc, argv, method_callable_method_entry(data));
     }
diff --git a/test/ruby/test_symbol.rb b/test/ruby/test_symbol.rb
index 540661afc0..ce3b0d652f 100644
--- a/test/ruby/test_symbol.rb
+++ b/test/ruby/test_symbol.rb
@@ -229,6 +229,35 @@ class TestSymbol < Test::Unit::TestCase
     assert_equal([false, false], m2.call(self, m2), "#{bug8531} nested without block")
   end
 
+  def test_block_curry_proc
+    assert_separately([], "#{<<-"begin;"}\n#{<<-"end;"}")
+    begin;
+    b = proc { true }.curry
+    assert(b.call, "without block")
+    assert(b.call { |o| o.to_s }, "with block")
+    assert(b.call(&:to_s), "with sym block")
+    end;
+  end
+
+  def test_block_curry_lambda
+    assert_separately([], "#{<<-"begin;"}\n#{<<-"end;"}")
+    begin;
+    b = lambda { true }.curry
+    assert(b.call, "without block")
+    assert(b.call { |o| o.to_s }, "with block")
+    assert(b.call(&:to_s), "with sym block")
+    end;
+  end
+
+  def test_block_method_to_proc
+    assert_separately([], "#{<<-"begin;"}\n#{<<-"end;"}")
+    begin;
+    b = method(:tap).to_proc
+    assert(b.call { |o| o.to_s }, "with block")
+    assert(b.call(&:to_s), "with sym block")
+    end;
+  end
+
   def test_succ
     assert_equal(:fop, :foo.succ)
   end
diff --git a/version.h b/version.h
index 0ea4b46ff5..e8531585af 100644
--- a/version.h
+++ b/version.h
@@ -1,6 +1,6 @@
 #define RUBY_VERSION "2.3.2"
 #define RUBY_RELEASE_DATE "2016-07-30"
-#define RUBY_PATCHLEVEL 140
+#define RUBY_PATCHLEVEL 141
 
 #define RUBY_RELEASE_YEAR 2016
 #define RUBY_RELEASE_MONTH 7