diff --git a/mlir/lib/Dialect/Linalg/Transforms/SplitReduction.cpp b/mlir/lib/Dialect/Linalg/Transforms/SplitReduction.cpp
index 8834000edd69b..61989f1eb7b29 100644
--- a/mlir/lib/Dialect/Linalg/Transforms/SplitReduction.cpp
+++ b/mlir/lib/Dialect/Linalg/Transforms/SplitReduction.cpp
@@ -297,7 +297,7 @@ FailureOr<SplitReductionResult> mlir::linalg::splitReductionByScaling(
     return b.notifyMatchFailure(op, "unknown reduction neutral");
 
   // TODO: relax this when multi-reduction support is available.
-  if (op.getNumOutputs() != neutralElements.size())
+  if (op.getNumOutputs() != (int)neutralElements.size())
     return b.notifyMatchFailure(op, "expect one reduction per output");
 
   // Rewrite part.