diff --git a/include/ftxui/screen/terminal.hpp b/include/ftxui/screen/terminal.hpp
index 9b4364c9..9a6b6e61 100644
--- a/include/ftxui/screen/terminal.hpp
+++ b/include/ftxui/screen/terminal.hpp
@@ -9,6 +9,7 @@ struct Dimensions {
 
 namespace Terminal {
 Dimensions Size();
+void SetFallbackSize(const Dimensions& fallbackSize);
 
 enum Color {
   Palette1,
diff --git a/src/ftxui/screen/terminal.cpp b/src/ftxui/screen/terminal.cpp
index 42497846..86410d3a 100644
--- a/src/ftxui/screen/terminal.cpp
+++ b/src/ftxui/screen/terminal.cpp
@@ -18,9 +18,18 @@
 
 namespace ftxui {
 
+#if defined(__EMSCRIPTEN__)
+static Dimensions fallback_size{140, 43};
+#elif defined(_WIN32)
+// The Microsoft default "cmd" returns errors above.
+static Dimensions fallback_size{80, 80};
+#else
+static Dimensions fallback_size{80, 25};
+#endif
+
 Dimensions Terminal::Size() {
 #if defined(__EMSCRIPTEN__)
-  return Dimensions{140, 43};
+  return fallback_size;
 #elif defined(_WIN32)
   CONSOLE_SCREEN_BUFFER_INFO csbi;
 
@@ -29,19 +38,24 @@ Dimensions Terminal::Size() {
                       csbi.srWindow.Bottom - csbi.srWindow.Top + 1};
   }
 
-  // The Microsoft default "cmd" returns errors above.
-  return Dimensions{80, 80};
+  return fallback_size;
 
 #else
   winsize w{};
   ioctl(STDOUT_FILENO, TIOCGWINSZ, &w);
   if (w.ws_col == 0 || w.ws_row == 0) {
-    return Dimensions{80, 25};
+    return fallback_size;
   }
   return Dimensions{w.ws_col, w.ws_row};
 #endif
 }
 
+/// @brief Override terminal size in case auto-detection fails
+/// @param fallbackSize Terminal dimensions to fallback to
+void Terminal::SetFallbackSize(const Dimensions& fallbackSize) {
+  fallback_size = fallbackSize;
+}
+
 namespace {
 
 const char* Safe(const char* c) {