diff --git a/src/Engine/gramambular2/reading_grid.h b/src/Engine/gramambular2/reading_grid.h
index 450eb8d..94057a5 100644
--- a/src/Engine/gramambular2/reading_grid.h
+++ b/src/Engine/gramambular2/reading_grid.h
@@ -267,8 +267,8 @@ class ReadingGrid {
                          Node::OverrideType overrideType);
 
   struct NodeInSpan {
-    NodePtr node;
-    size_t spanIndex;
+    NodePtr node = nullptr;
+    size_t spanIndex = 0;
   };
 
   // Find all nodes that overlap with the location. The return value is a list