diff --git a/paddle/operators/dropout_op.cc b/paddle/operators/dropout_op.cc
index 82e21408088bf1957f068c3eef491145233a594d..fe72aa56efe050aff19ad80e482451a415cb45a0 100644
--- a/paddle/operators/dropout_op.cc
+++ b/paddle/operators/dropout_op.cc
@@ -47,8 +47,8 @@ class DropoutOpMaker : public framework::OpProtoAndCheckerMaker {
     AddAttr<float>("dropout_prob", "Probability of setting units to zero.")
         .SetDefault(.5f)
         .AddCustomChecker([](const float& drop_p) {
-          PADDLE_ENFORCE(drop_p > 0.0f && drop_p < 1.0f,
-                         "'dropout_prob' must be between 0 and 1.");
+          PADDLE_ENFORCE(drop_p >= 0.0f && drop_p <= 1.0f,
+                         "'dropout_prob' must be between 0.0 and 1.0.");
         });
     AddAttr<bool>("is_test", "True if in test phase.").SetDefault(false);
     AddAttr<int>("seed", "Dropout random seed.").SetDefault(0);
diff --git a/paddle/operators/dropout_op.cu b/paddle/operators/dropout_op.cu
index c31d2195e95b116451b0f620f6582f65c0dae706..12e8e989e31919470b473ae3b5f3b99a64f25e9a 100644
--- a/paddle/operators/dropout_op.cu
+++ b/paddle/operators/dropout_op.cu
@@ -30,16 +30,15 @@ struct MaskGenerator {
   __host__ __device__ MaskGenerator(AttrType dropout_prob, int seed)
       : dropout_prob(dropout_prob), seed(seed) {}
 
-  __host__ __device__ T operator()(const unsigned int n) const {
+  inline __host__ __device__ T operator()(const unsigned int n) const {
     thrust::minstd_rand rng;
     rng.seed(seed);
     thrust::uniform_real_distribution<AttrType> dist(0, 1);
     rng.discard(n);
     if (dist(rng) < dropout_prob) {
       return static_cast<T>(0);
-    } else {
-      return static_cast<T>(1);
     }
+    return static_cast<T>(1);
   }
 };