diff --git a/test/Common/BitArrayTest.php b/test/Common/BitArrayTest.php
index 84aefc2..75e3b28 100644
--- a/test/Common/BitArrayTest.php
+++ b/test/Common/BitArrayTest.php
@@ -89,7 +89,7 @@ public function testGetNextSet4() : void
 
     public function testGetNextSet5() : void
     {
-        mt_srand(0xdeadbeef, MT_RAND_PHP);
+        mt_srand(0xdeadbeef);
 
         for ($i = 0; $i < 10; ++$i) {
             $array = new BitArray(mt_rand(1, 100));
diff --git a/test/Common/ReedSolomonCodecTest.php b/test/Common/ReedSolomonCodecTest.php
index 1c1b699..cdc4366 100644
--- a/test/Common/ReedSolomonCodecTest.php
+++ b/test/Common/ReedSolomonCodecTest.php
@@ -26,7 +26,7 @@ public static function tabs() : array
     #[DataProvider('tabs')]
     public function testCodec(int $symbolSize, int $generatorPoly, int $firstRoot, int $primitive, int $numRoots) : void
     {
-        mt_srand(0xdeadbeef, MT_RAND_PHP);
+        mt_srand(0xdeadbeef);
 
         $blockSize = (1 << $symbolSize) - 1;
         $dataSize  = $blockSize - $numRoots;
@@ -60,7 +60,7 @@ public function testCodec(int $symbolSize, int $generatorPoly, int $firstRoot, i
                 $errorValue = mt_rand(1, $blockSize);
 
                 do {
-                    $errorLocation = mt_rand(0, $blockSize);
+                    $errorLocation = mt_rand(0, $blockSize - 1);
                 } while (0 !== $errorLocations[$errorLocation]);
 
                 $errorLocations[$errorLocation] = 1;