diff --git a/tsdb/engine/tsm1/DESIGN.md b/tsdb/engine/tsm1/DESIGN.md
index 7b09922a2f..dfdff76cae 100644
--- a/tsdb/engine/tsm1/DESIGN.md
+++ b/tsdb/engine/tsm1/DESIGN.md
@@ -62,7 +62,7 @@ The last section is the footer that stores the offset of the start of the index.
 
 The file system is organized a directory per shard where each shard is integer number.  Within the shard dir exists a set of other directories and files:
 
-* wal Dir - Contains a set numerically increasing files WAL segment files name ######.wal.  The wal dir will be a separate location from the TSM data files so that different different types can be used if necessary.
+* wal Dir - Contains a set numerically increasing files WAL segment files name ######.wal.  The wal dir will be a separate location from the TSM data files so that different types can be used if necessary.
 * TSM files - A set of numerically increasing TSM files containing compressed series data.
 * Tombstone files - Files named after the corresponding TSM file as #####.tombstone.  These contain measurement and series keys that have been deleted.  These are removed during compactions.
 
diff --git a/tsdb/engine/tsm1/data_file.go b/tsdb/engine/tsm1/data_file.go
index aed8a4345f..f0da012798 100644
--- a/tsdb/engine/tsm1/data_file.go
+++ b/tsdb/engine/tsm1/data_file.go
@@ -108,7 +108,7 @@ type TSMIndex interface {
 	Entries(key string) []*IndexEntry
 
 	// Entry returns the index entry for the specified key and timestamp.  If no entry
-	// matches the key an timestamp, nil is returned.
+	// matches the key and timestamp, nil is returned.
 	Entry(key string, timestamp time.Time) *IndexEntry
 
 	// MarshalBinary returns a byte slice encoded version of the index.