diff --git a/src/slic3r/GUI/GLCanvas3D.cpp b/src/slic3r/GUI/GLCanvas3D.cpp
index 19c8135f5..071fd75b0 100644
--- a/src/slic3r/GUI/GLCanvas3D.cpp
+++ b/src/slic3r/GUI/GLCanvas3D.cpp
@@ -302,7 +302,10 @@ void GLCanvas3D::LayersEditing::render_variable_layer_height_dialog(const GLCanv
     ImGui::PushStyleColor(ImGuiCol_BorderActive, ImVec4(0.00f, 0.68f, 0.26f, 1.00f));
     ImGui::PushStyleColor(ImGuiCol_FrameBgHovered, ImVec4(0.00f, 0.68f, 0.26f, 0.00f));
     ImGui::PushStyleColor(ImGuiCol_FrameBgActive, ImVec4(0.00f, 0.68f, 0.26f, 0.00f));
-    ImGui::BBLDragScalar("##radius_input", ImGuiDataType_S32, &radius, 1, &v_min, &v_max);
+    if (ImGui::BBLDragScalar("##radius_input", ImGuiDataType_S32, &radius, 1, &v_min, &v_max)) {
+        radius = std::clamp(radius, 1, 10);
+        m_smooth_params.radius = (unsigned int)radius;
+    }
     ImGui::PopStyleColor(3);
 
     imgui.bbl_checkbox("##keep_min", m_smooth_params.keep_min);