diff --git a/paddle/fluid/operators/top_k_op.cc b/paddle/fluid/operators/top_k_op.cc
index e634f7c9a5794b7a8a5365cc9fc44eea7f07d89b..c80eaefaae621860626045b32b47f206259ae159 100644
--- a/paddle/fluid/operators/top_k_op.cc
+++ b/paddle/fluid/operators/top_k_op.cc
@@ -31,7 +31,7 @@ class TopkOp : public framework::OperatorWithKernel {
 
     auto input_dims = ctx->GetInputDim("X");
     PADDLE_ENFORCE_EQ(input_dims.size(), 2,
-                    "Rank of TopK op's input must be 2.");
+                      "Rank of TopK op's input must be 2.");
     const int k = static_cast<int>(ctx->Attrs().Get<int>("k"));
 
     PADDLE_ENFORCE_GE(k, 1, "k must >= 1");