diff --git a/examples/models/llama/runner/static_attention_io_manager.h b/examples/models/llama/runner/static_attention_io_manager.h
index 6f631df3ff0..83c80b48e1a 100644
--- a/examples/models/llama/runner/static_attention_io_manager.h
+++ b/examples/models/llama/runner/static_attention_io_manager.h
@@ -64,6 +64,8 @@ class StaticKVCache {
     update_data_ = allocator_.allocate(update_data_size_);
     ET_CHECK(cache_data_ != nullptr);
     ET_CHECK(update_data_ != nullptr);
+    std::fill(cache_data_, cache_data_ + cache_data_size_, T(0));
+    std::fill(update_data_, update_data_ + update_data_size_, T(0));
     init_ptrs();
   }
 
@@ -186,6 +188,7 @@ class StaticKVCache {
    */
   void reset() {
     std::fill(cache_pos_.begin(), cache_pos_.end(), 0);
+    std::fill(cache_data_, cache_data_ + cache_data_size_, T(0));
   }
 
  private:
@@ -613,6 +616,10 @@ class StaticAttentionIOManager {
         return config_.generate_full_logits ? input_len - 1 : 0;
       }
       std::copy(&tokens[i], &tokens[i + batch_len], input_buffer.begin());
+      if (batch_len < input_len) {
+        std::fill(
+            input_buffer.begin() + batch_len, input_buffer.end(), TokenT(0));
+      }
       if (!config_.generate_full_logits && config_.last_valid_token_pos_index) {
         last_valid_token_pos_ = batch_len - 1;
         set_input(