2 files changed, 8 insertions, 1 deletions
diff --git a/mrbgems/mruby-complex/src/complex.c b/mrbgems/mruby-complex/src/complex.c
index c6fb7a829..1b030c317 100644
--- a/mrbgems/mruby-complex/src/complex.c
+++ b/mrbgems/mruby-complex/src/complex.c
@@ -24,6 +24,7 @@ complex_new(mrb_state *mrb, mrb_float real, mrb_float imaginary)
   struct mrb_complex *p = complex_ptr(mrb, comp);
   p->real = real;
   p->imaginary = imaginary;
+  MRB_SET_FROZEN_FLAG(s);
 
   return comp;
 }
diff --git a/mrbgems/mruby-complex/test/complex.rb b/mrbgems/mruby-complex/test/complex.rb
index e7fcc7322..6996eb214 100644
--- a/mrbgems/mruby-complex/test/complex.rb
+++ b/mrbgems/mruby-complex/test/complex.rb
@@ -1,5 +1,5 @@
 def assert_complex(real, exp)
-  assert_float real.real,      exp.real           
+  assert_float real.real,      exp.real
   assert_float real.imaginary, exp.imaginary
 end
 
@@ -126,3 +126,9 @@ assert 'Complex::to_i' do
     Complex(1, 2).to_i
   end
 end
+
+assert 'Complex#frozen?' do
+  assert_predicate(1i, :frozen?)
+  assert_predicate(Complex(2,3), :frozen?)
+  assert_predicate(4+5i, :frozen?)
+end