diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
new file mode 100644
index 0000000..b865608
--- /dev/null
+++ b/.github/workflows/main.yml
@@ -0,0 +1,17 @@
+name: main
+on: [push, pull_request]
+jobs:
+  build:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ubuntu-latest, windows-latest, macos-latest]
+    steps:
+      - uses: actions/checkout@v2
+      - name: configure
+        run: cmake -B build -D CMAKE_BUILD_TYPE=Release 
+      - name: build
+        run: cmake --build build --parallel 2
+      # unfortunately the tests manipulate tap/tun drivers. This is not allowed in GA
+      # - name: test
+      #   run: cd build && ctest -VV
\ No newline at end of file
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 6d00514..d9655f2 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,6 +1,6 @@
 # libtuntap CMakeLists.txt
 # ========================
-cmake_minimum_required(VERSION 3.0)
+cmake_minimum_required(VERSION 3.5)
 
 project(libtuntap)
 
diff --git a/regress/CMakeLists.txt b/regress/CMakeLists.txt
index 98f120e..ad74745 100644
--- a/regress/CMakeLists.txt
+++ b/regress/CMakeLists.txt
@@ -14,27 +14,29 @@ foreach(SOURCE_FILE ${ALL_C_TESTS})
            COMMAND $<TARGET_FILE:${TEST_NAME}>)
 endforeach(SOURCE_FILE)
 
-# Shell based tests
+# Shell based tests (needs a posix shell)
 # -----------------
-file(GLOB ALL_SH_TESTS test*.sh)
-foreach(SOURCE_FILE ${ALL_SH_TESTS})
-  get_filename_component(TEST_NAME ${SOURCE_FILE} NAME_WE)
-  get_filename_component(TEST_SRC_PATH ${SOURCE_FILE} DIRECTORY)
+if (UNIX)
+  file(GLOB ALL_SH_TESTS test*.sh)
+  foreach(SOURCE_FILE ${ALL_SH_TESTS})
+    get_filename_component(TEST_NAME ${SOURCE_FILE} NAME_WE)
+    get_filename_component(TEST_SRC_PATH ${SOURCE_FILE} DIRECTORY)
 
-  string(REPLACE "test" "helper" HELPER_NAME ${TEST_NAME})
+    string(REPLACE "test" "helper" HELPER_NAME ${TEST_NAME})
 
-  if (EXISTS ${TEST_SRC_PATH}/${HELPER_NAME}.c)
-      add_executable(${HELPER_NAME} ${TEST_SRC_PATH}/${HELPER_NAME}.c)
-      target_link_libraries(${HELPER_NAME} tuntap)
-  endif()
-  add_test(NAME tuntap.${TEST_NAME}
-           COMMAND ${CMAKE_CURRENT_SOURCE_DIR}/${TEST_NAME}.sh)
-endforeach(SOURCE_FILE)
+    if (EXISTS ${TEST_SRC_PATH}/${HELPER_NAME}.c)
+        add_executable(${HELPER_NAME} ${TEST_SRC_PATH}/${HELPER_NAME}.c)
+        target_link_libraries(${HELPER_NAME} tuntap)
+    endif()
+    add_test(NAME tuntap.${TEST_NAME}
+            COMMAND ${CMAKE_CURRENT_SOURCE_DIR}/${TEST_NAME}.sh)
+  endforeach(SOURCE_FILE)
+endif()
 
 # "Will fail" tests
 # -----------------
 
-if(Darwin AND Windows)
+if(Darwin OR Windows)
   set_tests_properties(tuntap.test39 PROPERTIES WILL_FAIL true)
   set_tests_properties(tuntap.test40 PROPERTIES WILL_FAIL true)
 endif()
diff --git a/tuntap-windows.c b/tuntap-windows.c
index dc2c0db..6cdfffd 100644
--- a/tuntap-windows.c
+++ b/tuntap-windows.c
@@ -53,7 +53,7 @@ formated_error(LPWSTR pMessage, DWORD m, ...) {
     LPWSTR pBuffer = NULL;
 
     va_list args = NULL;
-    va_start(args, pMessage);
+    va_start(args, m);
 
     FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM |
                   FORMAT_MESSAGE_ALLOCATE_BUFFER,
diff --git a/tuntap.c b/tuntap.c
index 6c4e677..c59e438 100644
--- a/tuntap.c
+++ b/tuntap.c
@@ -70,7 +70,6 @@ tuntap_set_ip(struct device *dev, const char *addr, int netmask) {
 	t_tun_in_addr baddr4;
 	t_tun_in6_addr baddr6;
 	uint32_t mask;
-	int errval;
 
 	/* Only accept started device */
 	if (dev->tun_fd == TUNFD_INVALID_VALUE) {