diff --git a/tools/editor/editor_app.cpp b/tools/editor/editor_app.cpp
index 66817109..b2b7059a 100644
--- a/tools/editor/editor_app.cpp
+++ b/tools/editor/editor_app.cpp
@@ -1703,6 +1703,9 @@ void EditorApp::snapSelectedToGround() {
 void EditorApp::flattenAroundSelected(float radius) {
     auto* sel = objectPlacer_.getSelected();
     if (!sel || !terrain_.isLoaded()) return;
+    if (!std::isfinite(radius) || radius <= 0.0f ||
+        !std::isfinite(sel->position.x) || !std::isfinite(sel->position.y) ||
+        !std::isfinite(sel->position.z)) return;
 
     terrainEditor_.beginGeneratorUndo();
     float targetHeight = sel->position.z;
diff --git a/tools/editor/terrain_editor.cpp b/tools/editor/terrain_editor.cpp
index 88518a14..a5f57fcd 100644
--- a/tools/editor/terrain_editor.cpp
+++ b/tools/editor/terrain_editor.cpp
@@ -905,6 +905,9 @@ void TerrainEditor::createMesa(const glm::vec3& center, float radius, float heig
 
 void TerrainEditor::createHill(const glm::vec3& center, float radius, float height) {
     if (!terrain_) return;
+    if (!std::isfinite(center.x) || !std::isfinite(center.y) ||
+        !std::isfinite(radius) || radius <= 0.0f ||
+        !std::isfinite(height)) return;
     recordGeneratorUndo();
     for (int ci = 0; ci < 256; ci++) {
         auto& chunk = terrain_->chunks[ci];