diff --git a/src/libutil/util.cc b/src/libutil/util.cc
index 2a1272885..d29802bcd 100644
--- a/src/libutil/util.cc
+++ b/src/libutil/util.cc
@@ -1467,7 +1467,7 @@ static Sync<std::pair<unsigned short, unsigned short>> windowSize{{0, 0}};
 static void updateWindowSize()
 {
     struct winsize ws;
-    if (ioctl(1, TIOCGWINSZ, &ws) == 0) {
+    if (ioctl(2, TIOCGWINSZ, &ws) == 0) {
         auto windowSize_(windowSize.lock());
         windowSize_->first = ws.ws_row;
         windowSize_->second = ws.ws_col;
diff --git a/src/nix/progress-bar.cc b/src/nix/progress-bar.cc
index 5c05d6b22..661966733 100644
--- a/src/nix/progress-bar.cc
+++ b/src/nix/progress-bar.cc
@@ -341,7 +341,7 @@ public:
         }
 
         auto width = getWindowSize().second;
-        if (width <= 0) std::numeric_limits<decltype(width)>::max();
+        if (width <= 0) width = std::numeric_limits<decltype(width)>::max();
 
         writeToStderr("\r" + filterANSIEscapes(line, false, width) + "\e[K");
     }