diff --git a/internal/pkg/archive.go b/internal/pkg/archive.go
index ebda6dbf..8b5398fa 100644
--- a/internal/pkg/archive.go
+++ b/internal/pkg/archive.go
@@ -262,8 +262,8 @@ func Write(fsys fs.FS, root string, w io.Writer) error {
 	return aw.Close()
 }
 
-// HashFS returns a checksum produced by hashing the result of [Flatten].
-func HashFS(buf *Checksum, fsys fs.FS, root string) error {
+// SumFS saves checksum of the archive of fsys to the value pointed to by buf.
+func SumFS(buf *Checksum, fsys fs.FS, root string) error {
 	h := sha512.New384()
 	if err := Write(fsys, root, h); err != nil {
 		return err
@@ -272,7 +272,8 @@ func HashFS(buf *Checksum, fsys fs.FS, root string) error {
 	return nil
 }
 
-// HashDir returns a checksum produced by hashing the result of [Flatten].
-func HashDir(buf *Checksum, pathname *check.Absolute) error {
-	return HashFS(buf, os.DirFS(pathname.String()), ".")
+// SumDir saves checksum of the archive of directory at pathname to the value
+// pointed to by buf.
+func SumDir(buf *Checksum, pathname *check.Absolute) error {
+	return SumFS(buf, os.DirFS(pathname.String()), ".")
 }
diff --git a/internal/pkg/archive_test.go b/internal/pkg/archive_test.go
index a51cfee5..e04f3a66 100644
--- a/internal/pkg/archive_test.go
+++ b/internal/pkg/archive_test.go
@@ -141,10 +141,10 @@ func TestArchive(t *testing.T) {
 				t.Parallel()
 
 				var got pkg.Checksum
-				if err := pkg.HashFS(&got, tc.fsys, "."); err != nil {
-					t.Fatalf("HashFS: error = %v", err)
+				if err := pkg.SumFS(&got, tc.fsys, "."); err != nil {
+					t.Fatalf("SumFS: error = %v", err)
 				} else if got != tc.sum {
-					t.Fatalf("HashFS: %v", &pkg.ChecksumMismatchError{
+					t.Fatalf("SumFS: %v", &pkg.ChecksumMismatchError{
 						Got:  got,
 						Want: tc.sum,
 					})
diff --git a/internal/pkg/clean_test.go b/internal/pkg/clean_test.go
index 4b2385a3..e9124ab4 100644
--- a/internal/pkg/clean_test.go
+++ b/internal/pkg/clean_test.go
@@ -283,8 +283,8 @@ func TestClean(t *testing.T) {
 
 			want := tc.want.hash()
 			var checksum pkg.Checksum
-			if err = pkg.HashDir(&checksum, base); err != nil {
-				t.Fatalf("HashDir: error = %v", err)
+			if err = pkg.SumDir(&checksum, base); err != nil {
+				t.Fatalf("SumDir: error = %v", err)
 			} else if checksum != want {
 				t.Error(expectsFrom(base.String()))
 			}
diff --git a/internal/pkg/pkg.go b/internal/pkg/pkg.go
index d98b3753..8b022d1f 100644
--- a/internal/pkg/pkg.go
+++ b/internal/pkg/pkg.go
@@ -1007,7 +1007,7 @@ func (c *Cache) Scrub(checks int) error {
 
 				pathname := dir.Append(ent.Name())
 				if ent.IsDir() {
-					if err := HashDir(got, pathname); err != nil {
+					if err := SumDir(got, pathname); err != nil {
 						addErr(pathname, err)
 						return true
 					}
@@ -2132,7 +2132,7 @@ func (c *Cache) cure(a Artifact, curesExempt bool) (
 	}
 
 	var gotChecksum Checksum
-	if err = HashFS(
+	if err = SumFS(
 		&gotChecksum,
 		dotOverrideFS{os.DirFS(t.work.String()).(dirFS)},
 		".",
diff --git a/internal/pkg/pkg_test.go b/internal/pkg/pkg_test.go
index 35f858a5..25deb95c 100644
--- a/internal/pkg/pkg_test.go
+++ b/internal/pkg/pkg_test.go
@@ -357,7 +357,7 @@ type expectsFS fstest.MapFS
 
 // hash computes the checksum of e.
 func (e expectsFS) hash() (checksum pkg.Checksum) {
-	if err := pkg.HashFS(&checksum, fstest.MapFS(e), "."); err != nil {
+	if err := pkg.SumFS(&checksum, fstest.MapFS(e), "."); err != nil {
 		panic(err)
 	}
 	return
@@ -561,8 +561,8 @@ func checkWithCache(t *testing.T, testCases []cacheTestCase) {
 			want := tc.want.hash()
 
 			var checksum pkg.Checksum
-			if err := pkg.HashDir(&checksum, base); err != nil {
-				t.Fatalf("HashDir: error = %v", err)
+			if err := pkg.SumDir(&checksum, base); err != nil {
+				t.Fatalf("SumDir: error = %v", err)
 			} else if checksum != want {
 				t.Fatal(expectsFrom(base.String()))
 			}
@@ -581,8 +581,8 @@ func checkWithCache(t *testing.T, testCases []cacheTestCase) {
 			}
 
 			// validate again to make sure scrub did not condemn anything
-			if err := pkg.HashDir(&checksum, base); err != nil {
-				t.Fatalf("HashDir: error = %v", err)
+			if err := pkg.SumDir(&checksum, base); err != nil {
+				t.Fatalf("SumDir: error = %v", err)
 			} else if checksum != want {
 				t.Fatalf("(scrubbed) %s", expectsFrom(base.String()))
 			}
diff --git a/internal/uevent/coldboot_test.go b/internal/uevent/coldboot_test.go
index 4b38453a..0a50ead4 100644
--- a/internal/uevent/coldboot_test.go
+++ b/internal/uevent/coldboot_test.go
@@ -81,8 +81,8 @@ func TestColdboot(t *testing.T) {
 	}
 
 	var checksum pkg.Checksum
-	if err = pkg.HashDir(&checksum, check.MustAbs(d)); err != nil {
-		t.Fatalf("HashDir: error = %v", err)
+	if err = pkg.SumDir(&checksum, check.MustAbs(d)); err != nil {
+		t.Fatalf("SumDir: error = %v", err)
 	}
 
 	wantChecksum := pkg.MustDecode("mEy_Lf5KotThm7OwMx7yTKZh5HCCyaB41pVAvI9uDMgVQFM91iosBLYsRm8bDsX8")