1 files changed, 2 insertions, 1 deletions
diff --git a/parse_execution.cpp b/parse_execution.cpp
index 9267fb79..484d8741 100644
--- a/parse_execution.cpp
+++ b/parse_execution.cpp
@@ -72,7 +72,8 @@ node_offset_t parse_execution_context_t::get_offset(const parse_node_t &node) co
     const parse_node_t *addr = &node;
     const parse_node_t *base = &this->tree.at(0);
     assert(addr >= base);
-    node_offset_t offset = addr - base;
+    assert(addr - base < SOURCE_OFFSET_INVALID);
+    node_offset_t offset = static_cast<node_offset_t>(addr - base);
     assert(offset < this->tree.size());
     assert(&tree.at(offset) == &node);
     return offset;