diff --git a/src/crypto/cipher/gcm.go b/src/crypto/cipher/gcm.go
index c0ac9f163e..28f8b2093e 100644
--- a/src/crypto/cipher/gcm.go
+++ b/src/crypto/cipher/gcm.go
@@ -80,7 +80,7 @@ type gcm struct {
 // An exception is when the underlying Block was created by aes.NewCipher
 // on systems with hardware support for AES. See the crypto/aes package documentation for details.
 func NewGCM(cipher Block) (AEAD, error) {
-	return NewGCMWithNonceAndTagSize(cipher, gcmStandardNonceSize, gcmTagSize)
+	return newGCMWithNonceAndTagSize(cipher, gcmStandardNonceSize, gcmTagSize)
 }
 
 // NewGCMWithNonceSize returns the given 128-bit, block cipher wrapped in Galois
@@ -90,18 +90,22 @@ func NewGCM(cipher Block) (AEAD, error) {
 // cryptosystem that uses non-standard nonce lengths. All other users should use
 // NewGCM, which is faster and more resistant to misuse.
 func NewGCMWithNonceSize(cipher Block, size int) (AEAD, error) {
-	return NewGCMWithNonceAndTagSize(cipher, size, gcmTagSize)
+	return newGCMWithNonceAndTagSize(cipher, size, gcmTagSize)
 }
 
-// NewGCMWithNonceAndTagSize returns the given 128-bit, block cipher wrapped in Galois
-// Counter Mode, which accepts nonces of the given length and generates tags with the given length.
+// NewGCMWithTagSize returns the given 128-bit, block cipher wrapped in Galois
+// Counter Mode, which generates tags with the given length.
 //
 // Tag sizes between 12 and 16 bytes are allowed.
 //
 // Only use this function if you require compatibility with an existing
 // cryptosystem that uses non-standard tag lengths. All other users should use
 // NewGCM, which is more resistant to misuse.
-func NewGCMWithNonceAndTagSize(cipher Block, nonceSize, tagSize int) (AEAD, error) {
+func NewGCMWithTagSize(cipher Block, tagSize int) (AEAD, error) {
+	return newGCMWithNonceAndTagSize(cipher, gcmStandardNonceSize, tagSize)
+}
+
+func newGCMWithNonceAndTagSize(cipher Block, nonceSize, tagSize int) (AEAD, error) {
 	if tagSize < gcmMinimumTagSize || tagSize > gcmBlockSize {
 		return nil, errors.New("cipher: incorrect tag size given to GCM")
 	}
diff --git a/src/crypto/cipher/gcm_test.go b/src/crypto/cipher/gcm_test.go
index 31f4d95364..c48001db28 100644
--- a/src/crypto/cipher/gcm_test.go
+++ b/src/crypto/cipher/gcm_test.go
@@ -231,9 +231,28 @@ func TestAESGCM(t *testing.T) {
 		plaintext, _ := hex.DecodeString(test.plaintext)
 		ad, _ := hex.DecodeString(test.ad)
 		tagSize := (len(test.result) - len(test.plaintext)) / 2
-		aesgcm, err := cipher.NewGCMWithNonceAndTagSize(aes, len(nonce), tagSize)
-		if err != nil {
-			t.Fatal(err)
+
+		var aesgcm cipher.AEAD
+		switch {
+		// Handle non-standard nonce sizes
+		case tagSize != 16:
+			aesgcm, err = cipher.NewGCMWithTagSize(aes, tagSize)
+			if err != nil {
+				t.Fatal(err)
+			}
+
+		// Handle non-standard tag sizes
+		case len(nonce) != 12:
+			aesgcm, err = cipher.NewGCMWithNonceSize(aes, len(nonce))
+			if err != nil {
+				t.Fatal(err)
+			}
+
+		default:
+			aesgcm, err = cipher.NewGCM(aes)
+			if err != nil {
+				t.Fatal(err)
+			}
 		}
 
 		ct := aesgcm.Seal(nil, nonce, plaintext, ad)
@@ -277,12 +296,11 @@ func TestAESGCM(t *testing.T) {
 
 func TestGCMInvalidTagSize(t *testing.T) {
 	key, _ := hex.DecodeString("ab72c77b97cb5fe9a382d9fe81ffdbed")
-	nonce, _ := hex.DecodeString("54cc7dc2c37ec006bcc6d1db")
 
 	aes, _ := aes.NewCipher(key)
 
 	for _, tagSize := range []int{0, 1, aes.BlockSize() + 1} {
-		aesgcm, err := cipher.NewGCMWithNonceAndTagSize(aes, len(nonce), tagSize)
+		aesgcm, err := cipher.NewGCMWithTagSize(aes, tagSize)
 		if aesgcm != nil || err == nil {
 			t.Fatalf("NewGCMWithNonceAndTagSize was successful with an invalid %d-byte tag size", tagSize)
 		}