diff --git a/src/cryptsetup.c b/src/cryptsetup.c
index 9366f806..a003b11d 100644
--- a/src/cryptsetup.c
+++ b/src/cryptsetup.c
@@ -1242,6 +1242,21 @@ static int strcmp_or_null(const char *str, const char *expected)
 	return !str ? 0 : strcmp(str, expected);
 }
 
+static int get_adjusted_key_size(const char *cipher_mode, uint32_t default_size_bits, int integrity_keysize)
+{
+	uint32_t keysize_bits = opt_key_size;
+
+#ifdef ENABLE_LUKS_ADJUST_XTS_KEYSIZE
+	if (!opt_key_size && !strncmp(cipher_mode, "xts-", 4)) {
+		if (default_size_bits == 128)
+			keysize_bits = 256;
+		else if (default_size_bits == 256)
+			keysize_bits = 512;
+	}
+#endif
+	return (keysize_bits ?: default_size_bits) / 8 + integrity_keysize;
+}
+
 static int _luksFormat(struct crypt_device **r_cd, char **r_password, size_t *r_passwordLen)
 {
 	int r = -EINVAL, keysize, integrity_keysize = 0, fd, created = 0;
@@ -1374,15 +1389,7 @@ static int _luksFormat(struct crypt_device **r_cd, char **r_password, size_t *r_
 			goto out;
 	}
 
-#ifdef ENABLE_LUKS_ADJUST_XTS_KEYSIZE
-	if (!opt_key_size && !strncmp(cipher_mode, "xts-", 4)) {
-		if (DEFAULT_LUKS1_KEYBITS == 128)
-			opt_key_size = 256;
-		else if (DEFAULT_LUKS1_KEYBITS == 256)
-			opt_key_size = 512;
-	}
-#endif
-	keysize = (opt_key_size ?: DEFAULT_LUKS1_KEYBITS) / 8 + integrity_keysize;
+	keysize = get_adjusted_key_size(cipher_mode, DEFAULT_LUKS1_KEYBITS, integrity_keysize);
 
 	if (opt_random)
 		crypt_set_rng_type(cd, CRYPT_RNG_RANDOM);
@@ -3215,10 +3222,8 @@ static int action_reencrypt_luks2(struct crypt_device *cd)
 	if (r)
 		return r;
 
-	if (opt_key_size)
-		key_size = opt_key_size / 8;
-	else if (opt_cipher)
-		key_size = DEFAULT_LUKS1_KEYBITS / 8;
+	if (opt_key_size || opt_cipher)
+		key_size = get_adjusted_key_size(mode, DEFAULT_LUKS1_KEYBITS, 0);
 	else
 		key_size = crypt_get_volume_key_size(cd);
 
diff --git a/tests/luks2-reencryption-test b/tests/luks2-reencryption-test
index 93bddde7..56813b3c 100755
--- a/tests/luks2-reencryption-test
+++ b/tests/luks2-reencryption-test
@@ -654,7 +654,7 @@ function reencrypt_online_fixed_size() {
 }
 
 function setup_luks2_env() {
-	echo $PWD1 | $CRYPTSETUP luksFormat --type luks2 $FAST_PBKDF_ARGON $DEV || fail
+	echo $PWD1 | $CRYPTSETUP luksFormat --type luks2 -c aes-xts-plain64 $FAST_PBKDF_ARGON $DEV || fail
 	echo $PWD1 | $CRYPTSETUP open $DEV $DEV_NAME || fail
 	HAVE_KEYRING=$($CRYPTSETUP status $DEV_NAME | grep "key location: keyring")
 	if [ -n "$HAVE_KEYRING" ]; then
@@ -662,6 +662,8 @@ function setup_luks2_env() {
 	else
 		HAVE_KEYRING=0
 	fi
+	DEF_XTS_KEY=$($CRYPTSETUP status $DEV_NAME | grep "keysize:" | sed 's/\(  keysize: \)\([0-9]\+\)\(.*\)/\2/')
+	[ -n "$DEF_XTS_KEY" ] || fail "Failed to parse xts mode key size."
 	$CRYPTSETUP close $DEV_NAME || fail
 }
 
@@ -736,6 +738,8 @@ check_hash $PWD1 $HASH1
 echo $PWD1 | $CRYPTSETUP reencrypt $DEV -q -c aes-xts-plain64 --init-only $FAST_PBKDF_ARGON || fail
 echo $PWD1 | $CRYPTSETUP open $DEV $DEV_NAME || fail
 echo $PWD1 | $CRYPTSETUP reencrypt --active-name /dev/mapper/$DEV_NAME --resilience none -q || fail
+XTS_KEY=$($CRYPTSETUP status $DEV_NAME | grep "keysize:" | sed 's/\(  keysize: \)\([0-9]\+\)\(.*\)/\2/')
+[ "$XTS_KEY" -eq "$DEF_XTS_KEY" ] || fail "xts mode has wrong key size after reencryption ($XTS_KEY != expected $DEF_XTS_KEY)"
 echo $PWD1 | $CRYPTSETUP close $DEV_NAME || fail
 echo -n "[OK][4096 sector]"
 prepare sector_size=4096 dev_size_mb=32