diff --git a/.github/workflows/unit_test.yml b/.github/workflows/unit_test.yml
index 56c3e60..6127521 100644
--- a/.github/workflows/unit_test.yml
+++ b/.github/workflows/unit_test.yml
@@ -10,7 +10,7 @@ jobs:
   build_and_test:
     strategy:
       matrix:
-        os: [ubuntu-22.04, ubuntu-24.04, macos-13, macos-14, macos-15]
+        os: [ubuntu-22.04, ubuntu-24.04, macos-14, macos-15, macos-26]
     runs-on: ${{ matrix.os }}
     env:
       EXTRA_CMAKE_FLAGS: -DCMAKE_BUILD_TYPE=Release -DEDUCE_CORE_BUILD_TESTS=ON -DEDUCE_CORE_BUILD_EXAMPLES=ON
diff --git a/include/educelab/core/types/Mat.hpp b/include/educelab/core/types/Mat.hpp
index 6875e16..25ebc7d 100644
--- a/include/educelab/core/types/Mat.hpp
+++ b/include/educelab/core/types/Mat.hpp
@@ -26,7 +26,7 @@ class Mat
     static constexpr std::size_t cols{Cols};
 
     /** Default constructor */
-    Mat() { vals_.fill(0); };
+    Mat() { vals_.fill(0); }
 
     /** @brief Constructor with fill values */
     template <typename... Args>
diff --git a/include/educelab/core/utils/String.hpp b/include/educelab/core/utils/String.hpp
index 0b0d641..dda3b01 100644
--- a/include/educelab/core/utils/String.hpp
+++ b/include/educelab/core/utils/String.hpp
@@ -197,7 +197,7 @@ static auto split(std::string_view s, const Ds&... ds)
     // Split string
     std::vector<std::string_view> tokens;
     std::string_view::size_type begin{0};
-    for (const auto [end, size] : delimPos) {
+    for (const auto& [end, size] : delimPos) {
         // ignore nested delimiters
         if (end < begin) {
             continue;