diff --git a/src/interpreter/vmx.c b/src/interpreter/vmx.c
index 8beb0240..2137011e 100644
--- a/src/interpreter/vmx.c
+++ b/src/interpreter/vmx.c
@@ -3,7 +3,7 @@
 
 // importing io.h for tty detection in replinput
 #if defined(_WIN32) || defined(_WIN64)
-#include <io.h>
+#include <windows.h>
 #elif defined(__linux__) || defined(__APPLE__) || defined(__ANDROID__)
 #include <unistd.h>
 #endif
@@ -75,18 +75,23 @@ bool pk_wrapper__self(int argc, py_Ref argv) {
 
 // macro for tty-sensitiveness
 #if defined(_WIN32) || defined(_WIN64)
-#define istty(fd) _isatty(_fileno(fd))
+static inline int isatty_win(DWORD std_handle_id) {
+    HANDLE handle = GetStdHandle(std_handle_id); DWORD mode;
+    if (handle == INVALID_HANDLE_VALUE || handle == NULL) return 0; 
+    return GetConsoleMode(handle, &mode) != 0;
+}
+#define istty isatty_win(STD_INPUT_HANDLE)
 #elif defined(__linux__) || defined(__APPLE__) || defined(__ANDROID__)
-#define istty(fd) isatty(fileno(fd))
+#define istty isatty(0)
 #else
-#define istty(fd) 1 
+#define istty 1 
 #endif
 int py_replinput(char* buf, int max_size) {
     buf[0] = '\0';  // reset first char because we check '@' at the beginning
 
     int size = 0;
     bool multiline = false;
-    if (istty(stdin)) printf(">>> ");
+    if (istty) printf(">>> ");
 
     while(true) {
         int c = pk_current_vm->callbacks.getchr();
diff --git a/src2/main.c b/src2/main.c
index 453585b7..2d111791 100644
--- a/src2/main.c
+++ b/src2/main.c
@@ -10,13 +10,17 @@
 #endif
 
 #if defined(_WIN32) || defined(_WIN64)
-#include <io.h>
-#define istty(fd) _isatty(_fileno(fd))
+static inline int isatty_win(DWORD std_handle_id) {
+    HANDLE handle = GetStdHandle(std_handle_id); DWORD mode;
+    if (handle == INVALID_HANDLE_VALUE || handle == NULL) return 0; 
+    return GetConsoleMode(handle, &mode) != 0;
+}
+#define istty isatty_win(STD_INPUT_HANDLE)
 #elif defined(__linux__) || defined(__APPLE__) || defined(__ANDROID__)
 #include <unistd.h>
-#define istty(fd) isatty(fileno(fd))
+#define istty isatty(STDIN_FILENO)
 #else
-#define istty(fd) 1 
+#define istty 1 
 #endif
 
 static char* readfile(const char* path, int* data_size) {
@@ -96,7 +100,7 @@ int main(int argc, char** argv) {
         if(profile) printf("Warning: --profile is ignored in REPL mode.\n");
         if(debug) printf("Warning: --debug is ignored in REPL mode.\n");
 
-        if (istty(stdin)) {
+        if (istty) {
             printf("pocketpy " PK_VERSION " (" __DATE__ ", " __TIME__ ") ");
             printf("[%d bit] on %s", (int)(sizeof(void*) * 8), PY_SYS_PLATFORM_STRING);
 #ifndef NDEBUG
@@ -110,7 +114,7 @@ int main(int argc, char** argv) {
         while(true) {
             int size = py_replinput(buf, sizeof(buf));
             if(size == -1) {  // Ctrl-D (i.e. EOF)
-                if (istty(stdin)) printf("\n");
+                if (istty) printf("\n");
                 break;
             }
             assert(size < sizeof(buf));
@@ -172,4 +176,4 @@ int main(int argc, char** argv) {
     if(debug) py_debugger_exit(code);
     return code;
 }
-#undef istty
\ No newline at end of file
+#undef istty