diff --git a/lib/Dialect/mhlo/IR/hlo_ops.cc b/lib/Dialect/mhlo/IR/hlo_ops.cc
index e25538e..6b7b235 100644
--- a/lib/Dialect/mhlo/IR/hlo_ops.cc
+++ b/lib/Dialect/mhlo/IR/hlo_ops.cc
@@ -518,11 +518,19 @@ void ConvertOp::build(OpBuilder& builder, OperationState& result, Value operand,
 }
 
 OpFoldResult ConvertOp::fold(ArrayRef<Attribute> operands) {
-  if (getOperand().getType() == getResult().getType()) return getOperand();
+  auto operand_ty = getOperand().getType().cast<TensorType>();
+  auto result_ty = getResult().getType().cast<TensorType>();
+  if (operand_ty == result_ty) return getOperand();
 
   // If the result has non-static shape, a convert op is necessary to go from
   // static shape to non-static shape.
-  if (!getResult().getType().cast<TensorType>().hasStaticShape()) return {};
+  if (!result_ty.hasStaticShape()) return {};
+
+  // TODO(hinsu): Handle unsigned types.
+  if (operand_ty.getElementType().isUnsignedInteger() ||
+      result_ty.getElementType().isUnsignedInteger()) {
+    return {};
+  }
 
   // If the operand is constant, we can do the conversion now.
   if (auto elementsAttr = operands.front().dyn_cast_or_null<ElementsAttr>()) {