diff --git a/src/main/cpp/tiv.cpp b/src/main/cpp/tiv.cpp
index 8f89cdc..a5d6128 100644
--- a/src/main/cpp/tiv.cpp
+++ b/src/main/cpp/tiv.cpp
@@ -443,7 +443,7 @@ cimg_library::CImg<unsigned char> load_rgb_CImg(const char * const filename) {
 
 int main(int argc, char* argv[]) {
   struct winsize w;
-  ioctl(0, TIOCGWINSZ, &w);
+  ioctl(STDOUT_FILENO, TIOCGWINSZ, &w);
   
   int maxWidth = w.ws_col * 4;
   int maxHeight = w.ws_row * 8;