diff --git a/core/math/geometry_2d.cpp b/core/math/geometry_2d.cpp
index 48aa44b181..01ad6165b7 100644
--- a/core/math/geometry_2d.cpp
+++ b/core/math/geometry_2d.cpp
@@ -32,7 +32,9 @@
 
 #include "geometry_2d.h"
 
+GODOT_GCC_WARNING_PUSH_AND_IGNORE("-Walloc-zero")
 #include "thirdparty/clipper2/include/clipper2/clipper.h"
+GODOT_GCC_WARNING_POP
 #include "thirdparty/misc/polypartition.h"
 #define STB_RECT_PACK_IMPLEMENTATION
 #include "thirdparty/misc/stb_rect_pack.h"
diff --git a/scene/resources/packed_scene.cpp b/scene/resources/packed_scene.cpp
index 01fe9b45f4..e41faaf1ac 100644
--- a/scene/resources/packed_scene.cpp
+++ b/scene/resources/packed_scene.cpp
@@ -160,6 +160,7 @@ Node *SceneState::instantiate(GenEditState p_edit_state) const {
 	const NodeData *nd = &nodes[0];
 
 	Node **ret_nodes = (Node **)alloca(sizeof(Node *) * nc);
+	ret_nodes[0] = nullptr; // Sidesteps "maybe uninitialized" false-positives on GCC.
 
 	bool gen_node_path_cache = p_edit_state != GEN_EDIT_STATE_DISABLED && node_path_cache.is_empty();