diff --git a/flang-rt/include/flang-rt/runtime/io-stmt.h b/flang-rt/include/flang-rt/runtime/io-stmt.h
index a364ddfd9b3c7..33cc91271ab12 100644
--- a/flang-rt/include/flang-rt/runtime/io-stmt.h
+++ b/flang-rt/include/flang-rt/runtime/io-stmt.h
@@ -627,7 +627,7 @@ class OpenStatementState : public ExternalIoStatementBase {
   Fortran::common::optional<Action> action_;
   Convert convert_{Convert::Unknown};
   OwningPtr<char> path_;
-  std::size_t pathLength_;
+  std::size_t pathLength_{};
   Fortran::common::optional<bool> isUnformatted_;
   Fortran::common::optional<Access> access_;
 };