diff --git a/pkg/store/bucket.go b/pkg/store/bucket.go
index ac18f9d967..0d780fc2c7 100644
--- a/pkg/store/bucket.go
+++ b/pkg/store/bucket.go
@@ -2850,7 +2850,7 @@ func (r *bucketIndexReader) fetchPostings(ctx context.Context, keys []labels.Lab
 			r.stats.PostingsFetchDurationSum += time.Since(begin)
 			r.mtx.Unlock()
 
-			if rdr.Error() != nil {
+			if err := rdr.Error(); err != nil {
 				return errors.Wrap(err, "reading postings")
 			}
 			return nil
diff --git a/pkg/store/postings.go b/pkg/store/postings.go
index 28fbf0cf01..e44dfbe66c 100644
--- a/pkg/store/postings.go
+++ b/pkg/store/postings.go
@@ -49,7 +49,7 @@ func newPostingsReaderBuilder(ctx context.Context, r *bufio.Reader, postings []p
 }
 
 func getInt32(r io.Reader, buf []byte) (uint32, error) {
-	read, err := r.Read(buf)
+	read, err := io.ReadFull(r, buf)
 	if err != nil {
 		return 0, errors.Wrap(err, "reading")
 	}