diff --git a/git/githistory/fixtures_test.go b/git/githistory/fixtures_test.go
index b7eee22b..25f8c466 100644
--- a/git/githistory/fixtures_test.go
+++ b/git/githistory/fixtures_test.go
@@ -44,7 +44,7 @@ func AssertBlobContents(t *testing.T, db *odb.ObjectDatabase, tree, path, conten
 
 	// Then, iterating through each part of the filepath (i.e., a/b/c.txt ->
 	// []string{"a", "b", "c.txt"}).
-	parts := strings.Split(path, string(os.PathSeparator))
+	parts := strings.Split(path, "/")
 	for i := 0; i < len(parts)-1; i++ {
 		part := parts[i]
 
diff --git a/git/githistory/rewriter.go b/git/githistory/rewriter.go
index fc17519d..c118a2ed 100644
--- a/git/githistory/rewriter.go
+++ b/git/githistory/rewriter.go
@@ -4,8 +4,7 @@ import (
 	"encoding/hex"
 	"fmt"
 	"io"
-	"os"
-	"path/filepath"
+	"strings"
 	"sync"
 
 	"github.com/git-lfs/git-lfs/errors"
@@ -311,9 +310,14 @@ func (r *Rewriter) rewriteTree(commitOID []byte, treeOID []byte, path string, fn
 
 	entries := make([]*odb.TreeEntry, 0, len(tree.Entries))
 	for _, entry := range tree.Entries {
-		path := filepath.Join(path, entry.Name)
+		var epath string
+		if len(path) > 0 {
+			epath = strings.Join([]string{path, entry.Name}, "/")
+		} else {
+			epath = entry.Name
+		}
 
-		if !r.allows(entry.Type(), path) {
+		if !r.allows(entry.Type(), epath) {
 			entries = append(entries, entry)
 			continue
 		}
@@ -327,9 +331,9 @@ func (r *Rewriter) rewriteTree(commitOID []byte, treeOID []byte, path string, fn
 
 		switch entry.Type() {
 		case odb.BlobObjectType:
-			oid, err = r.rewriteBlob(commitOID, entry.Oid, path, fn, perc)
+			oid, err = r.rewriteBlob(commitOID, entry.Oid, epath, fn, perc)
 		case odb.TreeObjectType:
-			oid, err = r.rewriteTree(commitOID, entry.Oid, path, fn, tfn, perc)
+			oid, err = r.rewriteTree(commitOID, entry.Oid, epath, fn, tfn, perc)
 		default:
 			oid = entry.Oid
 
@@ -345,7 +349,7 @@ func (r *Rewriter) rewriteTree(commitOID []byte, treeOID []byte, path string, fn
 		}))
 	}
 
-	rewritten, err := tfn(string(os.PathSeparator)+path, &odb.Tree{Entries: entries})
+	rewritten, err := tfn("/"+path, &odb.Tree{Entries: entries})
 	if err != nil {
 		return nil, err
 	}
@@ -359,7 +363,7 @@ func (r *Rewriter) rewriteTree(commitOID []byte, treeOID []byte, path string, fn
 func (r *Rewriter) allows(typ odb.ObjectType, abs string) bool {
 	switch typ {
 	case odb.BlobObjectType:
-		return r.Filter().Allows(abs)
+		return r.Filter().Allows(strings.TrimPrefix(abs, "/"))
 	case odb.CommitObjectType, odb.TreeObjectType:
 		return true
 	default:
diff --git a/git/githistory/rewriter_test.go b/git/githistory/rewriter_test.go
index 4133bb68..0d570baf 100644
--- a/git/githistory/rewriter_test.go
+++ b/git/githistory/rewriter_test.go
@@ -3,9 +3,9 @@ package githistory
 import (
 	"bytes"
 	"encoding/hex"
+	"fmt"
 	"io"
 	"io/ioutil"
-	"path/filepath"
 	"reflect"
 	"strconv"
 	"strings"
@@ -165,7 +165,7 @@ func TestRewriterDoesntVisitUnchangedSubtrees(t *testing.T) {
 	assert.Nil(t, err)
 
 	assert.Equal(t, 2, seen["a.txt"])
-	assert.Equal(t, 1, seen[filepath.Join("subdir", "b.txt")])
+	assert.Equal(t, 1, seen["subdir/b.txt"])
 }
 
 func TestRewriterVisitsUniqueEntriesWithIdenticalContents(t *testing.T) {
@@ -189,6 +189,10 @@ func TestRewriterVisitsUniqueEntriesWithIdenticalContents(t *testing.T) {
 
 	tree := "bbbe0a7676523ae02234bfe874784ca2380c2d4b"
 
+	fmt.Println(hex.EncodeToString(tip))
+	root, _ := db.Root()
+	fmt.Println(root)
+
 	AssertCommitTree(t, db, hex.EncodeToString(tip), tree)
 
 	// After rewriting, the HEAD state of the repository should contain a