diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index c297b79..05c8f36 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -201,3 +201,35 @@ jobs:
         run: |
           g++ -std=c++11 -Wall -Wextra -I. -o TestConcoreHpp TestConcoreHpp.cpp
           ./TestConcoreHpp
+
+  cpp-test-windows:
+    runs-on: windows-latest
+    defaults:
+      run:
+        shell: msys2 {0}
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: msys2/setup-msys2@v2
+        with:
+          msystem: UCRT64
+          install: mingw-w64-ucrt-x86_64-gcc
+
+      - name: Build and run C++ tests
+        run: |
+          g++ -std=c++11 -I. -o TestLiteralEvalCpp TestLiteralEvalCpp.cpp
+          ./TestLiteralEvalCpp
+          g++ -std=c++11 -I. -o TestConcoreHpp TestConcoreHpp.cpp
+          ./TestConcoreHpp
+
+  cpp-test-macos:
+    runs-on: macos-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Build and run C++ tests
+        run: |
+          g++ -std=c++11 -I. -o TestLiteralEvalCpp TestLiteralEvalCpp.cpp
+          ./TestLiteralEvalCpp
+          g++ -std=c++11 -I. -o TestConcoreHpp TestConcoreHpp.cpp
+          ./TestConcoreHpp
diff --git a/concore.hpp b/concore.hpp
index ba676c0..a2f0261 100644
--- a/concore.hpp
+++ b/concore.hpp
@@ -246,7 +246,7 @@ class Concore{
      * @return The numeric part of the string.
      *         Returns -1 if the string does not contain a numeric part.
      */
-    key_t ExtractNumeric(const std::string& str) {
+    int ExtractNumeric(const std::string& str) {
         std::string numberString;
 
         // Find the number of leading digits in the input string
diff --git a/concoredocker.hpp b/concoredocker.hpp
index 108ba5f..f761dc9 100644
--- a/concoredocker.hpp
+++ b/concoredocker.hpp
@@ -242,7 +242,7 @@ class Concore {
             inpath + "/1/concore.maxtime", defaultValue);
     }
 
-    key_t ExtractNumeric(const std::string& str) {
+    int ExtractNumeric(const std::string& str) {
         std::string numberString;
         size_t numDigits = 0;
         while (numDigits < str.length() && std::isdigit(str[numDigits])) {