diff --git a/src/io/simple_dmatrix-inl.hpp b/src/io/simple_dmatrix-inl.hpp
index 5c1093540..8e89efdfb 100644
--- a/src/io/simple_dmatrix-inl.hpp
+++ b/src/io/simple_dmatrix-inl.hpp
@@ -158,8 +158,8 @@ class DMatrixSimple : public DataMatrix {
     if (!silent) {
       printf("%lux%lu matrix with %lu entries is loaded",
              static_cast<unsigned long>(info.num_row()),
-			 static_cast<unsigned long>(info.num_col()),
-			 static_cast<unsigned long>(row_data_.size()));
+             static_cast<unsigned long>(info.num_col()),
+             static_cast<unsigned long>(row_data_.size()));
       if (fname != NULL) {
         printf(" from %s\n", fname);
       } else {
@@ -188,11 +188,11 @@ class DMatrixSimple : public DataMatrix {
     if (!silent) {
       printf("%lux%lu matrix with %lu entries is saved to %s\n",
              static_cast<unsigned long>(info.num_row()),
-			 static_cast<unsigned long>(info.num_col()),
-			 static_cast<unsigned long>(row_data_.size()), fname);
+             static_cast<unsigned long>(info.num_col()),
+             static_cast<unsigned long>(row_data_.size()), fname);
       if (info.group_ptr.size() != 0) {
         printf("data contains %u groups\n",
-				static_cast<unsigned>(info.group_ptr.size()-1));
+               static_cast<unsigned>(info.group_ptr.size()-1));
       }
     }
   }