diff --git a/libraries/liblmdb/lmdb.h b/libraries/liblmdb/lmdb.h
index 2782101..30d5862 100644
--- a/libraries/liblmdb/lmdb.h
+++ b/libraries/liblmdb/lmdb.h
@@ -187,6 +187,11 @@ typedef	mode_t	mdb_mode_t;
 #endif
 
 #ifndef MDB_VL32
+/** Unsigned type used for mapsize, entry counts and page/transaction IDs.
+ *
+ *	It is normally size_t, hence the name. Defining MDB_VL32 makes it
+ *	uint64_t, but do not try this unless you know what you are doing.
+ */
 typedef size_t	mdb_size_t;
 # define MDB_SIZE_MAX	SIZE_MAX	/**< max #mdb_size_t */
 /** #mdb_size_t printf formats, \b t = one of [diouxX] without quotes */
diff --git a/libraries/liblmdb/mdb.c b/libraries/liblmdb/mdb.c
index 0d2889f..8e5b907 100644
--- a/libraries/liblmdb/mdb.c
+++ b/libraries/liblmdb/mdb.c
@@ -5414,7 +5414,7 @@ mdb_env_close(MDB_env *env)
 	free(env);
 }
 
-/** Compare two items pointing at aligned mdb_size_t's */
+/** Compare two items pointing at aligned #mdb_size_t's */
 static int
 mdb_cmp_long(const MDB_val *a, const MDB_val *b)
 {
@@ -5425,7 +5425,7 @@ mdb_cmp_long(const MDB_val *a, const MDB_val *b)
 /** Compare two items pointing at aligned unsigned int's.
  *
  *	This is also set as #MDB_INTEGERDUP|#MDB_DUPFIXED's #MDB_dbx.%md_dcmp,
- *	but #mdb_cmp_clong() is called instead if the data type is mdb_size_t.
+ *	but #mdb_cmp_clong() is called instead if the data type is #mdb_size_t.
  */
 static int
 mdb_cmp_int(const MDB_val *a, const MDB_val *b)