diff --git a/mlir/include/mlir/Dialect/LoopOps/LoopOps.td b/mlir/include/mlir/Dialect/LoopOps/LoopOps.td
--- a/mlir/include/mlir/Dialect/LoopOps/LoopOps.td
+++ b/mlir/include/mlir/Dialect/LoopOps/LoopOps.td
@@ -259,6 +259,7 @@
 def ParallelOp : Loop_Op<"parallel",
     [AttrSizedOperandSegments,
      DeclareOpInterfaceMethods<LoopLikeOpInterface>,
+     RecursiveSideEffects,
      SingleBlockImplicitTerminator<"YieldOp">]> {
   let summary = "parallel for operation";
   let description = [{