diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index dd714e801..c57f2d539 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -195,6 +195,7 @@ jobs:
         matrix:
           os:
             - ubuntu-24.04 # https://github.com/actions/runner-images/blob/main/images/ubuntu/Ubuntu2404-Readme.md
+            - ubuntu-24.04-arm # https://github.com/actions/runner-images/blob/main/images/ubuntu/Ubuntu2404-Arm64-Readme.md
             - macos-14 # https://github.com/actions/runner-images/blob/main/images/macos/macos-14-arm64-Readme.md
             - windows-2022 # https://github.com/actions/runner-images/blob/main/images/windows/Windows2022-Readme.md
           python-version:
@@ -223,6 +224,19 @@ jobs:
               os: windows-2022
               cibuildwheel: "cp312"
 
+            # avoid unnecessary use of arm resources
+            - is-full-run: false
+              os: ubuntu-24.04-arm
+              cibuildwheel: "cp310"
+
+            - is-full-run: false
+              os: ubuntu-24.04-arm
+              cibuildwheel: "cp311"
+
+            - is-full-run: false
+              os: ubuntu-24.04-arm
+              cibuildwheel: "cp312"
+
             # avoid unnecessary use of mac resources
             - is-full-run: false
               os: macos-14
@@ -412,6 +426,7 @@ jobs:
         matrix:
           os:
             - ubuntu-24.04
+            - ubuntu-24.04-arm
             - macos-14
             - windows-2022
           python-version:
@@ -440,6 +455,19 @@ jobs:
               os: windows-2022
               python-version: "3.12"
 
+            # avoid unnecessary use of arm resources
+            - is-full-run: false
+              os: ubuntu-24.04-arm
+              python-version: "3.10"
+
+            - is-full-run: false
+              os: ubuntu-24.04-arm
+              python-version: "3.11"
+
+            - is-full-run: false
+              os: ubuntu-24.04-arm
+              python-version: "3.12"
+
             # avoid unnecessary use of mac resources
             - is-full-run: false
               os: macos-14
diff --git a/cpp/csp/python/NumpyInputAdapter.h b/cpp/csp/python/NumpyInputAdapter.h
index b7e87cefa..d1332f8c9 100644
--- a/cpp/csp/python/NumpyInputAdapter.h
+++ b/cpp/csp/python/NumpyInputAdapter.h
@@ -250,13 +250,13 @@ void NumpyInputAdapter<int64_t>::setValue( int64_t & value, void * data )
     {
         case NPY_BYTELTR:
         {
-            const char * const val = (const char *) data;
+            const int8_t * const val = (const int8_t *) data;
             value = static_cast<int64_t>(*val);
             break;
         }
         case NPY_UBYTELTR:
         {
-            const unsigned char * const val = (const unsigned char *) data;
+            const uint8_t * const val = (const uint8_t *) data;
             value = static_cast<int64_t>(*val);
             break;
         }
diff --git a/csp/tests/test_build.py b/csp/tests/test_build.py
index 1ece657aa..bf810e7b8 100644
--- a/csp/tests/test_build.py
+++ b/csp/tests/test_build.py
@@ -1,7 +1,34 @@
+import runpy
+import subprocess
+import sys
 import unittest
+from pathlib import Path
+from types import ModuleType
+from unittest.mock import Mock, patch
 
 
 class TestBuild(unittest.TestCase):
+    def test_arm64_linux_uses_arm64_vcpkg_triplet(self):
+        skbuild = ModuleType("skbuild")
+        skbuild.setup = Mock()
+        setup_path = Path(__file__).parents[2] / "setup.py"
+
+        with (
+            patch.dict(sys.modules, {"skbuild": skbuild}),
+            patch.object(sys, "platform", "linux"),
+            patch("platform.machine", return_value="aarch64"),
+            patch("platform.system", return_value="Linux"),
+            patch.object(
+                subprocess,
+                "check_output",
+                return_value=b"9c5c2a0ab75aff5bcd08142525f6ff7f6f7ddeee\n",
+            ),
+        ):
+            runpy.run_path(setup_path, run_name="csp_setup_test")
+
+        cmake_args = skbuild.setup.call_args.kwargs["cmake_args"]
+        self.assertIn("-DVCPKG_TARGET_TRIPLET=arm64-linux", cmake_args)
+
     def test_init_helpers(self):
         """was a build issue where InitHelpers ran on a single instance across all libraries linking _cspimpl"""
         # Take a sample of libraries
diff --git a/setup.py b/setup.py
index 47564c353..f88428635 100644
--- a/setup.py
+++ b/setup.py
@@ -32,7 +32,7 @@
 )
 
 if sys.platform == "linux":
-    VCPKG_TRIPLET = "x64-linux"
+    VCPKG_TRIPLET = "arm64-linux" if platform.machine().lower() in ("aarch64", "arm64") else "x64-linux"
 elif sys.platform == "win32":
     VCPKG_TRIPLET = "x64-windows-static-md"
 else: