diff --git a/src/alloc.c b/src/alloc.c
index 3f9fa0ac..e8543a96 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -405,6 +405,7 @@ char* mi_strndup(const char* s, size_t n) mi_attr_noexcept {
 #define PATH_MAX MAX_PATH
 #endif
 #include <windows.h>
+#include <errno.h>
 char* mi_heap_realpath(mi_heap_t* heap, const char* fname, char* resolved_name) mi_attr_noexcept {
   // todo: use GetFullPathNameW to allow longer file names
   char buf[PATH_MAX];
diff --git a/src/init.c b/src/init.c
index 6d8c21e9..7023e3b5 100644
--- a/src/init.c
+++ b/src/init.c
@@ -385,7 +385,7 @@ static void mi_process_done(void) {
 
 #if defined(_WIN32) && defined(MI_SHARED_LIB)
   // Windows DLL: easy to hook into process_init and thread_done
-  #include <Windows.h>
+  #include <windows.h>
 
   __declspec(dllexport) BOOL WINAPI DllMain(HINSTANCE inst, DWORD reason, LPVOID reserved) {
     if (reason==DLL_PROCESS_ATTACH) {