diff --git a/tools/editor/object_placer.cpp b/tools/editor/object_placer.cpp
index 3d29dfa4..86b4d0ef 100644
--- a/tools/editor/object_placer.cpp
+++ b/tools/editor/object_placer.cpp
@@ -176,6 +176,17 @@ void ObjectPlacer::deleteSelected() {
 void ObjectPlacer::scatter(const glm::vec3& center, float radius, int count,
                             float minScale, float maxScale) {
     if (activePath_.empty()) return;
+    // Defensive bounds — UI sliders cap these, but the function is also
+    // callable programmatically. count > 100k would freeze the editor;
+    // minScale >= maxScale violates uniform_real_distribution preconditions.
+    if (count <= 0 || count > 100'000) return;
+    if (!std::isfinite(radius) || radius < 0.0f) return;
+    if (!std::isfinite(center.x) || !std::isfinite(center.y) ||
+        !std::isfinite(center.z)) return;
+    if (!std::isfinite(minScale) || !std::isfinite(maxScale)) return;
+    if (minScale <= 0.0f) minScale = 0.01f;
+    if (maxScale < minScale) maxScale = minScale + 0.01f;
+
     std::mt19937 rng(static_cast<uint32_t>(center.x * 100 + center.y * 37 + objects_.size()));
     std::uniform_real_distribution<float> distAngle(0.0f, 6.2831853f);
     std::uniform_real_distribution<float> distDist(0.0f, 1.0f);