diff --git a/flang/lib/Lower/OpenACC.cpp b/flang/lib/Lower/OpenACC.cpp
index 474d4e686c135..d619d47fc2359 100644
--- a/flang/lib/Lower/OpenACC.cpp
+++ b/flang/lib/Lower/OpenACC.cpp
@@ -1974,6 +1974,7 @@ genACC(Fortran::lower::AbstractConverter &converter,
 
   assert(loopDirective.v == llvm::acc::ACCD_loop &&
          "Unsupported OpenACC loop construct");
+  (void)loopDirective;
 
   const auto &accClauseList =
       std::get<Fortran::parser::AccClauseList>(beginLoopDirective.t);