diff --git a/paddle/function/BufferArg.h b/paddle/function/BufferArg.h
index 9c792c6bb72aa27fb78519497c3da05452050575..84209265ce7634121e3e4dde609cd787093c45ec 100644
--- a/paddle/function/BufferArg.h
+++ b/paddle/function/BufferArg.h
@@ -192,6 +192,7 @@ public:
   SequenceIdArg(const TensorShape& shape, ArgType argType = UNSPECIFIED)
       : BufferArg(VALUE_TYPE_INT32, shape, argType) {
     CHECK_EQ(shape_.ndims(), (size_t)1);
+    CHECK_GT(shape_[0], 1);
     numSeqs_ = shape_[0] - 1;
   }
 
diff --git a/paddle/function/FunctionTest.cpp b/paddle/function/FunctionTest.cpp
index 03c609b524277763b73c2e100d9d9c5081c7d3f6..fdf7e631e5ab8c67eb5cf906bd0af49740d60112 100644
--- a/paddle/function/FunctionTest.cpp
+++ b/paddle/function/FunctionTest.cpp
@@ -85,6 +85,7 @@ void testBufferArgs(const BufferArgs& inputs,
 }
 
 void testBufferArgs(const BufferArgs& inputs, const CheckBufferArg& check) {
+  EXPECT_EQ(inputs.size(), 1);
   check(inputs[0]);
 }
 
diff --git a/paddle/function/FunctionTest.h b/paddle/function/FunctionTest.h
index 412e3a7d1b30a775ee329da2dcfe82462f156984..24e7a36a43cfa8941535cb778aa1557ec5a0a6f4 100644
--- a/paddle/function/FunctionTest.h
+++ b/paddle/function/FunctionTest.h
@@ -172,7 +172,7 @@ protected:
 
   void initArg(SequenceIdArg& arg, size_t batchSize) {
     size_t numSeqs = arg.numSeqs();
-    int* buf = (int*)arg.data();
+    int* buf = reinterpret_cast<int*>(arg.data());
     int pos = 0;
     size_t maxLen = 2 * batchSize / numSeqs;
     for (int i = 0; i < (int)numSeqs; ++i) {