diff --git a/tests/Math/BigInteger/BCMathTest.php b/tests/Math/BigInteger/BCMathTest.php
index 6440550b..08d4b3fe 100644
--- a/tests/Math/BigInteger/BCMathTest.php
+++ b/tests/Math/BigInteger/BCMathTest.php
@@ -14,7 +14,8 @@ class Math_BigInteger_BCMathTest extends Math_BigInteger_TestCase
 			self::markTestSkipped('BCMath extension is not available.');
 		}
 
-		self::ensureModeConstant('MATH_BIGINTEGER_MODE', MATH_BIGINTEGER_MODE_BCMATH);
 		parent::setUpBeforeClass();
+
+		self::ensureModeConstant('MATH_BIGINTEGER_MODE', MATH_BIGINTEGER_MODE_BCMATH);
 	}
 }
diff --git a/tests/Math/BigInteger/GMPTest.php b/tests/Math/BigInteger/GMPTest.php
index c8895271..fcd898d1 100644
--- a/tests/Math/BigInteger/GMPTest.php
+++ b/tests/Math/BigInteger/GMPTest.php
@@ -14,7 +14,8 @@ class Math_BigInteger_GMPTest extends Math_BigInteger_TestCase
 			self::markTestSkipped('GNU Multiple Precision (GMP) extension is not available.');
 		}
 
-		self::ensureModeConstant('MATH_BIGINTEGER_MODE', MATH_BIGINTEGER_MODE_GMP);
 		parent::setUpBeforeClass();
+
+		self::ensureModeConstant('MATH_BIGINTEGER_MODE', MATH_BIGINTEGER_MODE_GMP);
 	}
 }
diff --git a/tests/Math/BigInteger/InternalTest.php b/tests/Math/BigInteger/InternalTest.php
index dcdc9129..1ca2ef74 100644
--- a/tests/Math/BigInteger/InternalTest.php
+++ b/tests/Math/BigInteger/InternalTest.php
@@ -9,7 +9,8 @@ class Math_BigInteger_InternalTest extends Math_BigInteger_TestCase
 {
 	static public function setUpBeforeClass()
 	{
-		self::ensureModeConstant('MATH_BIGINTEGER_MODE', MATH_BIGINTEGER_MODE_INTERNAL);
 		parent::setUpBeforeClass();
+
+		self::ensureModeConstant('MATH_BIGINTEGER_MODE', MATH_BIGINTEGER_MODE_INTERNAL);
 	}
 }
diff --git a/tests/Math/BigInteger/TestCase.php b/tests/Math/BigInteger/TestCase.php
index 74a92663..01edc475 100644
--- a/tests/Math/BigInteger/TestCase.php
+++ b/tests/Math/BigInteger/TestCase.php
@@ -9,6 +9,13 @@ require_once 'Math/BigInteger.php';
 
 abstract class Math_BigInteger_TestCase extends PhpseclibTestCase
 {
+	static public function setUpBeforeClass()
+	{
+		parent::setUpBeforeClass();
+
+		self::reRequireFile('Math/BigInteger.php');
+	}
+
 	public function getInstance($x = 0, $base = 10)
 	{
 		return new Math_BigInteger($x, $base);
diff --git a/tests/PhpseclibTestCase.php b/tests/PhpseclibTestCase.php
index 196e87dd..e69aa25a 100644
--- a/tests/PhpseclibTestCase.php
+++ b/tests/PhpseclibTestCase.php
@@ -48,4 +48,27 @@ abstract class PhpseclibTestCase extends PHPUnit_Framework_TestCase
 			define($constant, $expected);
 		}
 	}
+
+	/**
+	* @param string $filename
+	*
+	* @return null
+	*/
+	static protected function reRequireFile($filename)
+	{
+		if (function_exists('runkit_import'))
+		{
+			$result = runkit_import(
+				$filename,
+				RUNKIT_IMPORT_FUNCTIONS |
+				RUNKIT_IMPORT_CLASS_METHODS |
+				RUNKIT_IMPORT_OVERRIDE
+			);
+
+			if (!$result)
+			{
+				self::markTestSkipped("Failed to reimport file $filename");
+			}
+		}
+	}
 }