diff --git a/storage/innobase/include/fil0fil.h b/storage/innobase/include/fil0fil.h
index 09496a2c5ca..5dbf5e99400 100644
--- a/storage/innobase/include/fil0fil.h
+++ b/storage/innobase/include/fil0fil.h
@@ -207,7 +207,7 @@ public:
     return remove_within_range(range, value);
   }
   /** Add the value within the existing range
-  @param[in]	range_set::add_rangerange	range to be modified
+  @param[in]	range	range to be modified
   @param[in]	value	value to be added */
   range_set_t::iterator add_within_range(range_set_t::iterator range,
                                          uint32_t value)
diff --git a/storage/innobase/mtr/mtr0mtr.cc b/storage/innobase/mtr/mtr0mtr.cc
index 32e31ee84f4..66b6d2976b8 100644
--- a/storage/innobase/mtr/mtr0mtr.cc
+++ b/storage/innobase/mtr/mtr0mtr.cc
@@ -354,7 +354,9 @@ struct mtr_write_log_t {
 /** Start a mini-transaction. */
 void mtr_t::start()
 {
+  MEM_CHECK_DEFINED(&m_freed_ranges, sizeof m_freed_ranges);
   UNIV_MEM_INVALID(this, sizeof *this);
+  UNIV_MEM_VALID(&m_freed_ranges, sizeof m_freed_ranges);
 
   ut_d(m_start= true);
   ut_d(m_commit= false);