diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index a8d19a2a..d0819741 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -4,7 +4,7 @@ jobs:
   test:
     strategy:
       matrix:
-        go-version: [1.14.x, 1.19.x, 1.20.x]
+        go-version: [1.17.x, 1.19.x, 1.20.x]
         os: [ubuntu-latest, windows-latest, macos-latest]
 
     runs-on: ${{ matrix.os }}
diff --git a/fontscan/scandir_go1.16.go b/fontscan/scandir.go
similarity index 96%
rename from fontscan/scandir_go1.16.go
rename to fontscan/scandir.go
index ed725aa9..79ac703e 100644
--- a/fontscan/scandir_go1.16.go
+++ b/fontscan/scandir.go
@@ -1,6 +1,3 @@
-//go:build go1.16
-// +build go1.16
-
 package fontscan
 
 import (
diff --git a/fontscan/scandir_old.go b/fontscan/scandir_old.go
deleted file mode 100644
index 7f14565e..00000000
--- a/fontscan/scandir_old.go
+++ /dev/null
@@ -1,131 +0,0 @@
-//go:build !go1.16
-// +build !go1.16
-
-package fontscan
-
-import (
-	"os"
-	"path/filepath"
-)
-
-// recursively walk through the given directory, scanning font files and calling dst.consume
-// for each valid file found.
-func (dst *footprintScanner) scanDirectory(logger Logger, dir string, visited map[string]bool) error {
-	walkFn := func(path string, d os.FileInfo, err error) error {
-		if err != nil {
-			logger.Printf("error walking font directory %q: %v", path, err)
-			return filepath.SkipDir
-		}
-
-		if d.IsDir() { // keep going
-			return nil
-		}
-
-		if visited[path] {
-			return nil // skip the path
-		}
-		visited[path] = true
-
-		// load the information, following potential symoblic links
-		info, err := os.Stat(path)
-		if err != nil {
-			return err
-		}
-
-		// always ignore files which should never be font files
-		if ignoreFontFile(info.Name()) {
-			return nil
-		}
-
-		err = dst.consume(path, info)
-
-		return err
-	}
-
-	err := filepath.Walk(dir, walkFn)
-
-	return err
-}
-
-// DirEntry is a copy of the Go 1.16+ fs.DirEntry interface.
-type dirEntry interface {
-	// Name returns the name of the file (or subdirectory) described by the entry.
-	// This name is only the final element of the path (the base name), not the entire path.
-	// For example, Name would return "hello.go" not "home/gopher/hello.go".
-	Name() string
-
-	// IsDir reports whether the entry describes a directory.
-	IsDir() bool
-
-	// Type returns the type bits for the entry.
-	// The type bits are a subset of the usual FileMode bits, those returned by the FileMode.Type method.
-	Type() os.FileMode
-
-	// Info returns the FileInfo for the file or subdirectory described by the entry.
-	// The returned FileInfo may be from the time of the original directory read
-	// or from the time of the call to Info. If the file has been removed or renamed
-	// since the directory read, Info may return an error satisfying errors.Is(err, ErrNotExist).
-	// If the entry denotes a symbolic link, Info reports the information about the link itself,
-	// not the link's target.
-	Info() (os.FileInfo, error)
-}
-
-// dirEntryAdapter wraps a normal os.FileInfo to be compatible with the DirEntry interface.
-type dirEntryAdapter struct {
-	os.FileInfo
-}
-
-func (e dirEntryAdapter) Info() (os.FileInfo, error) {
-	return e.FileInfo, nil
-}
-
-// Type copies the constants from modern Go's fs package and uses them to provide a file's
-// Type.
-// https://cs.opensource.google/go/go/+/refs/tags/go1.20.5:src/io/fs/fs.go;l=239
-func (e dirEntryAdapter) Type() os.FileMode {
-	// The defined file mode bits are the most significant bits of the FileMode.
-	// The nine least-significant bits are the standard Unix rwxrwxrwx permissions.
-	// The values of these bits should be considered part of the public API and
-	// may be used in wire protocols or disk representations: they must not be
-	// changed, although new bits might be added.
-	const (
-		// The single letters are the abbreviations
-		// used by the String method's formatting.
-		ModeDir        os.FileMode = 1 << (32 - 1 - iota) // d: is a directory
-		ModeAppend                                        // a: append-only
-		ModeExclusive                                     // l: exclusive use
-		ModeTemporary                                     // T: temporary file; Plan 9 only
-		ModeSymlink                                       // L: symbolic link
-		ModeDevice                                        // D: device file
-		ModeNamedPipe                                     // p: named pipe (FIFO)
-		ModeSocket                                        // S: Unix domain socket
-		ModeSetuid                                        // u: setuid
-		ModeSetgid                                        // g: setgid
-		ModeCharDevice                                    // c: Unix character device, when ModeDevice is set
-		ModeSticky                                        // t: sticky
-		ModeIrregular                                     // ?: non-regular file; nothing else is known about this file
-
-		// Mask for the type bits. For regular files, none will be set.
-		ModeType = ModeDir | ModeSymlink | ModeNamedPipe | ModeSocket | ModeDevice | ModeCharDevice | ModeIrregular
-	)
-
-	return e.FileInfo.Mode() & ModeType
-}
-
-// readDir re-implements os.ReadDir (Go 1.16+) using only Go 1.14's stdlib.
-func readDir(name string) ([]dirEntry, error) {
-	d, err := os.Open(name)
-	if err != nil {
-		return nil, err
-	}
-	defer d.Close()
-	entries, err := d.Readdir(0)
-	if err != nil {
-		return nil, err
-	}
-	adapted := make([]dirEntry, len(entries))
-	for i, e := range entries {
-		adapted[i] = dirEntryAdapter{e}
-	}
-	return adapted, nil
-}
diff --git a/opentype/testutils/utils.go b/opentype/testutils/utils.go
index d90e9611..31de6b56 100644
--- a/opentype/testutils/utils.go
+++ b/opentype/testutils/utils.go
@@ -1,6 +1,4 @@
 // SPDX-License-Identifier: Unlicense OR BSD-3-Clause
-//go:build go1.16
-// +build go1.16
 
 package testutils