diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 642c5c3..febb798 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -2,19 +2,20 @@ name: build
 on: [push, pull_request]
 jobs:
   build:
-    runs-on: ubuntu-latest
+    runs-on: ${{ matrix.os }}
     strategy:
       fail-fast: false
       matrix:
         include:
-          - ruby: 3.3
-            gemfile: gemfiles/rails80.gemfile
           - ruby: 3.3
             gemfile: Gemfile
+            os: ubuntu-latest
           - ruby: 3.2
-            gemfile: gemfiles/rails71.gemfile
+            gemfile: Gemfile
+            os: macos-latest
           - ruby: 3.1
-            gemfile: gemfiles/rails70.gemfile
+            gemfile: Gemfile
+            os: windows-latest
     env:
       BUNDLE_GEMFILE: ${{ matrix.gemfile }}
     steps:
diff --git a/ext/field_test/ext.cpp b/ext/field_test/ext.cpp
index 408c9db..fb3d6f2 100644
--- a/ext/field_test/ext.cpp
+++ b/ext/field_test/ext.cpp
@@ -1,16 +1,66 @@
-#include <rice/rice.hpp>
-#include <rice/stl.hpp>
+#include <ruby.h>
 
 #include "bayestest.hpp"
 
 using bayestest::BinaryTest;
 
+void binary_test_free(void* data)
+{
+  free(data);
+}
+
+size_t binary_test_size(const void* data)
+{
+  // does not currently include size of variants
+  return sizeof(BinaryTest);
+}
+
+static const rb_data_type_t binary_test_type = {
+  .wrap_struct_name = "binary_test",
+  .function = {
+    .dmark = NULL,
+    .dfree = binary_test_free,
+    .dsize = binary_test_size,
+  },
+  .data = NULL,
+  .flags = RUBY_TYPED_FREE_IMMEDIATELY,
+};
+
+VALUE binary_test_alloc(VALUE self)
+{
+  BinaryTest* data = new BinaryTest();
+
+  return TypedData_Wrap_Struct(self, &binary_test_type, data);
+}
+
+VALUE binary_test_add(VALUE self, VALUE participants, VALUE conversions)
+{
+  BinaryTest* data;
+  TypedData_Get_Struct(self, BinaryTest, &binary_test_type, data);
+
+  data->add(NUM2INT(participants), NUM2INT(conversions));
+
+  return Qnil;
+}
+
+VALUE binary_test_probabilities(VALUE self)
+{
+  BinaryTest* data;
+  TypedData_Get_Struct(self, BinaryTest, &binary_test_type, data);
+
+  VALUE arr = rb_ary_new();
+  for (auto &v : data->probabilities()) {
+    rb_ary_push(arr, DBL2NUM(v));
+  }
+  return arr;
+}
+
 extern "C"
 void Init_ext() {
-  auto rb_mFieldTest = Rice::define_module("FieldTest");
+  auto mFieldTest = rb_define_module("FieldTest");
 
-  Rice::define_class_under<BinaryTest>(rb_mFieldTest, "BinaryTest")
-    .define_constructor(Rice::Constructor<BinaryTest>())
-    .define_method("add", &BinaryTest::add)
-    .define_method("probabilities", &BinaryTest::probabilities);
+  auto cBinaryTest = rb_define_class_under(mFieldTest, "BinaryTest", rb_cObject);
+  rb_define_alloc_func(cBinaryTest, binary_test_alloc);
+  rb_define_method(cBinaryTest, "add", binary_test_add, 2);
+  rb_define_method(cBinaryTest, "probabilities", binary_test_probabilities, 0);
 }
diff --git a/ext/field_test/extconf.rb b/ext/field_test/extconf.rb
index 43cbc28..1bcb145 100644
--- a/ext/field_test/extconf.rb
+++ b/ext/field_test/extconf.rb
@@ -1,4 +1,4 @@
-require "mkmf-rice"
+require "mkmf"
 
 $CXXFLAGS << " -std=c++17 $(optflags)"
 
diff --git a/field_test.gemspec b/field_test.gemspec
index 4ec83df..6c7078a 100644
--- a/field_test.gemspec
+++ b/field_test.gemspec
@@ -19,5 +19,4 @@ Gem::Specification.new do |spec|
   spec.add_dependency "railties", ">= 7"
   spec.add_dependency "activerecord", ">= 7"
   spec.add_dependency "browser", ">= 2"
-  spec.add_dependency "rice", ">= 4.0.2"
 end