diff --git a/selfdrive/modeld/models/dmonitoring.cc b/selfdrive/modeld/models/dmonitoring.cc
index 4f1f345689..7e8d635101 100644
--- a/selfdrive/modeld/models/dmonitoring.cc
+++ b/selfdrive/modeld/models/dmonitoring.cc
@@ -71,6 +71,7 @@ DMonitoringResult dmonitoring_eval_frame(DMonitoringModelState* s, void* stream_
                        cropped_u_buf, cropped_width/2,
                        cropped_v_buf, cropped_width/2,
                        cropped_width, cropped_height);
+    delete[] premirror_cropped_buf;
   }
 
   uint8_t *resized_buf = new uint8_t[resized_width*resized_height*3/2];