diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 91064150..e196b2a2 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 }}
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])