diff --git a/runtime/gc/collector/semi_space.cc b/runtime/gc/collector/semi_space.cc
index a355d40..ed63ed0 100644
--- a/runtime/gc/collector/semi_space.cc
+++ b/runtime/gc/collector/semi_space.cc
@@ -89,14 +89,24 @@
 SemiSpace::SemiSpace(Heap* heap, bool generational, const std::string& name_prefix)
     : GarbageCollector(heap,
                        name_prefix + (name_prefix.empty() ? "" : " ") + "marksweep + semispace"),
+      mark_stack_(nullptr),
+      is_large_object_space_immune_(false),
       to_space_(nullptr),
+      to_space_live_bitmap_(nullptr),
       from_space_(nullptr),
+      mark_bitmap_(nullptr),
+      self_(nullptr),
       generational_(generational),
       last_gc_to_space_end_(nullptr),
       bytes_promoted_(0),
       bytes_promoted_since_last_whole_heap_collection_(0),
       large_object_bytes_allocated_at_last_whole_heap_collection_(0),
       collect_from_space_only_(generational),
+      promo_dest_space_(nullptr),
+      fallback_space_(nullptr),
+      bytes_moved_(0U),
+      objects_moved_(0U),
+      saved_bytes_(0U),
       collector_name_(name_),
       swap_semi_spaces_(true) {
 }