diff --git a/mdbx.h b/mdbx.h
index 14b7513d..3959faa7 100644
--- a/mdbx.h
+++ b/mdbx.h
@@ -136,7 +136,7 @@ are only a few cases of changing data.
 | _DELETING_|||
 |Key is absent → Error since no such key      |\ref mdbx_del() or \ref mdbx_replace()|Error \ref MDBX_NOTFOUND|
 |Key exist → Delete by key                    |\ref mdbx_del() with the parameter `data = NULL`|Deletion|
-|Key exist → Delete by key with with data matching check|\ref mdbx_del() with the parameter `data` filled with the value which should be match for deletion|Deletion or \ref MDBX_NOTFOUND if the value does not match|
+|Key exist → Delete by key with data matching check|\ref mdbx_del() with the parameter `data` filled with the value which should be match for deletion|Deletion or \ref MDBX_NOTFOUND if the value does not match|
 |Delete at the current cursor position        |\ref mdbx_cursor_del() with \ref MDBX_CURRENT flag|Deletion|
 |Extract (read & delete) value by the key     |\ref mdbx_replace() with zero flag and parameter `new_data = NULL`|Returning a deleted value|
 
@@ -1414,7 +1414,7 @@ enum MDBX_env_flags_t {
    * \ref mdbx_env_set_syncbytes() and \ref mdbx_env_set_syncperiod() functions
    * could be very useful with `MDBX_SAFE_NOSYNC` flag.
    *
-   * The number and volume of of disk IOPs with MDBX_SAFE_NOSYNC flag will
+   * The number and volume of disk IOPs with MDBX_SAFE_NOSYNC flag will
    * exactly the as without any no-sync flags. However, you should expect a
    * larger process's [work set](https://bit.ly/2kA2tFX) and significantly worse
    * a [locality of reference](https://bit.ly/2mbYq2J), due to the more
@@ -5266,7 +5266,7 @@ LIBMDBX_API int mdbx_dbi_sequence(MDBX_txn *txn, MDBX_dbi dbi, uint64_t *result,
  * This returns a comparison as if the two data items were keys in the
  * specified database.
  *
- * \warning There ss a Undefined behavior if one of arguments is invalid.
+ * \warning There is a Undefined behavior if one of arguments is invalid.
  *
  * \param [in] txn   A transaction handle returned by \ref mdbx_txn_begin().
  * \param [in] dbi   A database handle returned by \ref mdbx_dbi_open().
@@ -5291,7 +5291,7 @@ mdbx_get_keycmp(MDBX_db_flags_t flags);
  * This returns a comparison as if the two items were data items of the
  * specified database.
  *
- * \warning There ss a Undefined behavior if one of arguments is invalid.
+ * \warning There is a Undefined behavior if one of arguments is invalid.
  *
  * \param [in] txn   A transaction handle returned by \ref mdbx_txn_begin().
  * \param [in] dbi   A database handle returned by \ref mdbx_dbi_open().
diff --git a/mdbx.h++ b/mdbx.h++
index f8c8db61..a4a12d32 100644
--- a/mdbx.h++
+++ b/mdbx.h++
@@ -878,7 +878,7 @@ struct LIBMDBX_API_TYPE slice : public ::MDBX_val {
   /// \brief Checks whether the content of the slice is printable.
   /// \param [in] disable_utf8 By default if `disable_utf8` is `false` function
   /// checks that content bytes are printable ASCII-7 characters or a valid UTF8
-  /// sequences. Otherwise, if if `disable_utf8` is `true` function checks that
+  /// sequences. Otherwise, if `disable_utf8` is `true` function checks that
   /// content bytes are printable extended 8-bit ASCII codes.
   MDBX_NOTHROW_PURE_FUNCTION bool
   is_printable(bool disable_utf8 = false) const noexcept;
diff --git a/src/internals.h b/src/internals.h
index 564465d9..1324187d 100644
--- a/src/internals.h
+++ b/src/internals.h
@@ -891,7 +891,7 @@ typedef struct MDBX_reader {
 /* The header for the reader table (a memory-mapped lock file). */
 typedef struct MDBX_lockinfo {
   /* Stamp identifying this as an MDBX file.
-   * It must be set to MDBX_MAGIC with with MDBX_LOCK_VERSION. */
+   * It must be set to MDBX_MAGIC with MDBX_LOCK_VERSION. */
   uint64_t mti_magic_and_version;
 
   /* Format of this lock file. Must be set to MDBX_LOCK_FORMAT. */