diff --git a/ext/openssl/ossl_pkey_ec.c b/ext/openssl/ossl_pkey_ec.c
index bb19533ed..35f031819 100644
--- a/ext/openssl/ossl_pkey_ec.c
+++ b/ext/openssl/ossl_pkey_ec.c
@@ -702,7 +702,7 @@ static VALUE ossl_ec_group_initialize(int argc, VALUE *argv, VALUE self)
 
         break;
       default:
-        ossl_raise(rb_eArgError, "wrong number of arguments");
+        ossl_raise(rb_eArgError, "wrong number of arguments (given %d, expected 1 or 4)", argc);
     }
 
     ASSUME(group);
diff --git a/test/openssl/test_pkey_ec.rb b/test/openssl/test_pkey_ec.rb
index 88085bc68..ec97a747a 100644
--- a/test/openssl/test_pkey_ec.rb
+++ b/test/openssl/test_pkey_ec.rb
@@ -345,6 +345,15 @@ def test_ec_group
     assert_equal group1.degree, group4.degree
   end
 
+  def test_ec_group_initialize_error_message
+    # Test that passing 2 arguments raises the helpful error
+    e = assert_raise(ArgumentError) do
+      OpenSSL::PKey::EC::Group.new(:GFp, 123)
+    end
+
+    assert_equal("wrong number of arguments (given 2, expected 1 or 4)", e.message)
+  end
+
   def test_ec_point
     group = OpenSSL::PKey::EC::Group.new("prime256v1")
     key = OpenSSL::PKey::EC.generate(group)