diff --git a/.travis.yml b/.travis.yml
index 8ef7cae6..30b3d3de 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -19,13 +19,7 @@ matrix:
     - php: nightly
 
 install:
-  - wget http://ftp.gnu.org/gnu/parallel/parallel-20170822.tar.bz2
-  - tar -xvjf parallel*
-  - cd parallel-20170822
-  - ./configure
-  - make
-  - sudo make install
-  - cd ..
+  - phpenv config-rm xdebug.ini
   - eval `ssh-agent -s`
   - travis/setup-secure-shell.sh
   - sh -c "if [ '$TRAVIS_PHP_VERSION' != 'hhvm' -a `php -r "echo (int) version_compare(PHP_VERSION, '7.0', '<');"` = "1" ]; then travis/install-php-extensions.sh; fi"
diff --git a/tests/Unit/Crypt/DSA/CreateKeyTest.php b/tests/Unit/Crypt/DSA/CreateKeyTest.php
index 103be760..bf3a190e 100644
--- a/tests/Unit/Crypt/DSA/CreateKeyTest.php
+++ b/tests/Unit/Crypt/DSA/CreateKeyTest.php
@@ -14,7 +14,7 @@ use phpseclib3\Crypt\DSA\PrivateKey;
 /**
  * @requires PHP 7.0
  */
-class Unit_Crypt_DSA_CreateKeyTest extends PhpseclibTestCase
+class Unit_Crypt_DSA_CreateKeyTestDSA extends PhpseclibTestCase
 {
     public function testCreateParameters()
     {
diff --git a/tests/Unit/Crypt/EC/CurveTest.php b/tests/Unit/Crypt/EC/CurveTest.php
index 93d20d64..1a8a2cc8 100644
--- a/tests/Unit/Crypt/EC/CurveTest.php
+++ b/tests/Unit/Crypt/EC/CurveTest.php
@@ -11,6 +11,7 @@ use phpseclib3\File\ASN1;
 use phpseclib3\Crypt\EC\Curves\Ed448;
 use phpseclib3\Math\BigInteger;
 use phpseclib3\Crypt\PublicKeyLoader;
+use phpseclib3\Common\Functions\Strings;
 
 class Ed448PublicKey
 {
@@ -18,6 +19,10 @@ class Ed448PublicKey
 
     public static function load($key, $password = '')
     {
+        if (!Strings::is_stringable($key)) {
+            throw new \UnexpectedValueException('Key should be a string - not a ' . gettype($key));
+        }
+
         $components = ['curve' => new Ed448()];
         $components['QA'] = self::extractPoint($key, $components['curve']);
 
@@ -29,6 +34,10 @@ class Ed448PrivateKey
 {
     public static function load($key, $password = '')
     {
+        if (!Strings::is_stringable($key)) {
+            throw new \UnexpectedValueException('Key should be a string - not a ' . gettype($key));
+        }
+
         $components = ['curve' => new Ed448()];
         $components['dA'] = $components['curve']->extractSecret($key);
         $components['QA'] = $components['curve']->multiplyPoint($components['curve']->getBasePoint(), $components['dA']);
diff --git a/tests/Unit/Crypt/RSA/CreateKeyTest.php b/tests/Unit/Crypt/RSA/CreateKeyTest.php
index 7c56312f..b6c030be 100644
--- a/tests/Unit/Crypt/RSA/CreateKeyTest.php
+++ b/tests/Unit/Crypt/RSA/CreateKeyTest.php
@@ -11,7 +11,7 @@ use phpseclib3\Crypt\RSA\Formats\Keys\PKCS1;
 use phpseclib3\Crypt\RSA\PrivateKey;
 use phpseclib3\Crypt\RSA\PublicKey;
 
-class Unit_Crypt_RSA_CreateKeyTest extends PhpseclibTestCase
+class Unit_Crypt_RSA_CreateKeyTestRSA extends PhpseclibTestCase
 {
     public function testCreateKey()
     {
diff --git a/travis/run-phpunit.sh b/travis/run-phpunit.sh
index 672a396f..7fb7eefc 100755
--- a/travis/run-phpunit.sh
+++ b/travis/run-phpunit.sh
@@ -38,15 +38,8 @@ then
     find tests -type f -name "*.php" -print0 | xargs -0 sed -i 's/^class Functional_Net_/class /g'
 fi
 
-if [ "$TRAVIS_PHP_VERSION" = 'hhvm' -o `php -r "echo (int) version_compare(PHP_VERSION, '7.0', '>=');"` = "1" ]
-then
-  find tests -type f -name "*Test.php" | \
-    parallel --gnu --keep-order \
-      "echo '== {} =='; \"$PHPUNIT\" $PHPUNIT_ARGS {};"
-else
-  "$PHPUNIT" \
-    $PHPUNIT_ARGS \
-    --coverage-text \
-    --coverage-clover code_coverage/clover.xml \
-    --coverage-html code_coverage/
-fi
+"$PHPUNIT" \
+  $PHPUNIT_ARGS \
+  --coverage-text \
+  --coverage-clover code_coverage/clover.xml \
+  --coverage-html code_coverage/