diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 91064150..430790cc 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -5,14 +5,12 @@ on: [push, pull_request]
 jobs:
   MRI:
     name: ${{ matrix.os }} ruby-${{ matrix.ruby }}
-    runs-on: ${{ matrix.os }}
+    runs-on: ${{ matrix.os }}-latest
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu-latest, macos-11, windows-2022]
-        ruby: [ '2.5', '2.6', '2.7', '3.0', '3.1', '3.2', '3.3', head]
-        include:
-          - { os: windows-2022 , ruby: mswin }
+        os: ['ubuntu', 'macos', 'windows']
+        ruby: ['2.6', '2.7', '3.0', '3.1', '3.2', '3.3', '3.4', head]
     steps:
       - uses: actions/checkout@v4
       - name: Set up Ruby ${{ matrix.ruby }}
@@ -59,7 +57,7 @@ jobs:
           sudo apt-get -y install podman
           podman pull fedora:rawhide
       - name: Get source
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           path: 'numo-narray'
       - name: Create container and run tests
@@ -75,6 +73,7 @@ jobs:
               echo 'RUN gem build numo-narray.gemspec'
               echo 'RUN gem install numo-narray-*.gem'
               echo 'RUN bundle install'
+              echo 'RUN bundle exec rake compile'
               echo 'RUN bundle exec rake test'
           } > podmanfile
           podman build --tag fedora_test -f ./podmanfile
diff --git a/ext/numo/narray/ndloop.c b/ext/numo/narray/ndloop.c
index 7a3b74c4..58cc0b52 100644
--- a/ext/numo/narray/ndloop.c
+++ b/ext/numo/narray/ndloop.c
@@ -56,7 +56,7 @@ typedef struct NA_MD_LOOP {
     VALUE  reduce;
     VALUE  loop_opt;
     ndfunc_t  *ndfunc;
-    void (*loop_func)();
+    void (*loop_func)(ndfunc_t *, struct NA_MD_LOOP *);
 } na_md_loop_t;
 
 #define LARG(lp,iarg) ((lp)->user.args[iarg])
diff --git a/ext/numo/narray/numo/types/xint_macro.h b/ext/numo/narray/numo/types/xint_macro.h
index 1bd6e6b0..35b920b5 100644
--- a/ext/numo/narray/numo/types/xint_macro.h
+++ b/ext/numo/narray/numo/types/xint_macro.h
@@ -3,8 +3,9 @@
 
 #define m_extract(x)    m_data_to_num(*(dtype*)(x))
 
-#define m_from_double(x) (x)
-#define m_from_real(x) (x)
+/* Handle negative values consistently across platforms for unsigned integer types */
+#define m_from_double(x) ((x) < 0 ? (dtype)((long long)(x)) : (dtype)(x))
+#define m_from_real(x) ((x) < 0 ? (dtype)((long long)(x)) : (dtype)(x))
 #define m_from_sint(x) (x)
 #define m_from_int32(x) (x)
 #define m_from_int64(x) (x)
diff --git a/test/narray_test.rb b/test/narray_test.rb
index da96c464..3a1e2a21 100644
--- a/test/narray_test.rb
+++ b/test/narray_test.rb
@@ -142,9 +142,9 @@ class NArrayTest < Test::Unit::TestCase
         assert { a.sum == 29 }
         if float_types.include?(dtype)
           assert { a.mean == 29.0/6 }
-          assert { a.var == 13.766666666666669 }
-          assert { a.stddev == 3.710345895825168 }
-          assert { a.rms == 5.901977069875258 }
+          assert_in_delta(a.var, 13.766666666666669, 1e-14)
+          assert_in_delta(a.stddev, 3.710345895825168, 1e-14)
+          assert_in_delta(a.rms, 5.901977069875258, 1e-14)
         end
         assert { a.dup.fill(12) == [12]*6 }
         assert { (a + 1) == [2,3,4,6,8,12] }