diff --git a/imgui_demo.cpp b/imgui_demo.cpp
index 7ecb03693..a1eb682c1 100644
--- a/imgui_demo.cpp
+++ b/imgui_demo.cpp
@@ -966,10 +966,12 @@ void ImGui::ShowTestWindow(bool* opened)
         {
             ImGui::Bullet(); ImGui::TextWrapped("Horizontal scrolling for a window has to be enabled explicitly via the ImGuiWindowFlags_HorizontalScrollbar flag.");
             ImGui::Bullet(); ImGui::TextWrapped("You may want to explicitly specify content width by calling SetNextWindowContentWidth() before Begin().");
+            static int lines = 7;
+            ImGui::SliderInt("Lines", &lines, 1, 15);
             ImGui::PushStyleVar(ImGuiStyleVar_FrameRounding, 3.0f);
             ImGui::PushStyleVar(ImGuiStyleVar_FramePadding, ImVec2(2.0f, 1.0f));
             ImGui::BeginChild("scrolling", ImVec2(0, ImGui::GetItemsLineHeightWithSpacing()*7 + 30), true, ImGuiWindowFlags_HorizontalScrollbar);
-            for (int line = 0; line < 7; line++)
+            for (int line = 0; line < lines; line++)
             {
                 // Display random stuff
                 int num_buttons = 10 + ((line & 1) ? line * 9 : line * 3);