diff --git a/src/Driver/ExecDriver.php b/src/Driver/ExecDriver.php
index 3349858..64df7ce 100644
--- a/src/Driver/ExecDriver.php
+++ b/src/Driver/ExecDriver.php
@@ -2,6 +2,7 @@
 
 namespace BigFileTools\Driver;
 use Brick\Math\BigInteger;
+use Brick\Math\Exception\ArithmeticException;
 
 class ExecDriver implements ISizeDriver
 {
@@ -41,36 +42,50 @@ public function getFileSize($path)
 		}
 	}
 
+	/**
+	 * Convert string into integer
+	 * Must be precise number, otherwise you will see and exception.
+	 *
+	 * @param $valueAsString
+	 * @return BigInteger
+	 * @throws Exception
+	 */
+	private function convertToInteger($valueAsString) {
+		if(!is_string($valueAsString)) {
+			throw new Exception("Cannot convert to integer. Expected string, but got " . gettype($valueAsString). ".");
+		}
+		$trimmedInput = trim($valueAsString);
+
+		try {
+			return BigInteger::of($trimmedInput);
+
+		} catch (ArithmeticException $e) {
+			throw new Exception("Returned value cannot be converted to an integer.",0, $e);
+		}
+
+	}
+
 	private function getFileSizeWindows($path)
 	{
 		$escapedPath = escapeshellarg($path);
-		$size = trim(exec("for %F in ($escapedPath) do @echo %~zF"));
-		if ($size AND ctype_digit($size)) {
-			return BigInteger::of($size);
-		} else {
-			throw new Exception("Exec returned invalid value");
-		}
+		return $this->convertToInteger(
+			exec("for %F in ($escapedPath) do @echo %~zF")
+		);
 	}
 
 	private function getFileSizeLinux($path)
 	{
 		$escapedPath = escapeshellarg($path);
-		$size = trim(exec("stat -Lc%s $escapedPath"));
-		if ($size AND ctype_digit($size)) {
-			return BigInteger::of($size);
-		} else {
-			throw new Exception("Exec returned invalid value");
-		}
+		return $this->convertToInteger(
+			exec("stat -Lc%s $escapedPath")
+		);
 	}
 
 	private function getFileSizeMac($path)
 	{
 		$escapedPath = escapeshellarg($path);
-		$size = trim(exec("stat -f%z $escapedPath"));
-		if ($size AND ctype_digit($size)) {
-			return BigInteger::of($size);
-		} else {
-			throw new Exception("Exec returned invalid value");
-		}
+		return $this->convertToInteger(
+			exec("stat -f%z $escapedPath")
+		);
 	}
 }
\ No newline at end of file
diff --git a/tests/BigFileTools/Driver/BaseDriverTest.php b/tests/BigFileTools/Driver/BaseDriverTest.php
index d7f61e8..c423f12 100644
--- a/tests/BigFileTools/Driver/BaseDriverTest.php
+++ b/tests/BigFileTools/Driver/BaseDriverTest.php
@@ -34,6 +34,14 @@ protected function setUp()
 	 */
 	abstract protected function getDriver();
 
+	public function testFileEmpty() {
+		Assert::equal(
+			TESTS_EMPTY_FILE_SIZE,
+			(string) $this->driver->getFileSize(TESTS_EMPTY_FILE_PATH),
+			"Driver " . get_class($this->getDriver()) . "Failed for file empty file."
+		);
+	}
+
 	public function testFileSmall_Under2_31bites() {
 		Assert::equal(
 			TESTS_SMALL_FILE_SIZE,
diff --git a/tests/bootstrap.php b/tests/bootstrap.php
index 8a2b8cb..7fae6f2 100644
--- a/tests/bootstrap.php
+++ b/tests/bootstrap.php
@@ -4,6 +4,9 @@
 
 Tester\Environment::setup();
 
+define("TESTS_EMPTY_FILE_PATH", __DIR__ . "/temp/emptyfile.tmp"); // 0B
+define("TESTS_EMPTY_FILE_SIZE", "0");
+
 define("TESTS_SMALL_FILE_PATH", __DIR__ . "/temp/smallfile.tmp"); // 1M (less then 2^31)
 define("TESTS_SMALL_FILE_SIZE", "1048576");
 
diff --git a/tests/setup-linux.sh b/tests/setup-linux.sh
index e13b8fd..283af42 100644
--- a/tests/setup-linux.sh
+++ b/tests/setup-linux.sh
@@ -6,6 +6,7 @@
 
 bash tests/cleanup.sh
 
+touch tests/temp/emptyfile.tmp
 truncate -s 1M tests/temp/smallfile.tmp
 truncate -s 2050M tests/temp/mediumfile.tmp
 truncate -s 4100M tests/temp/bigfile.tmp
diff --git a/tests/setup-osx.sh b/tests/setup-osx.sh
index da4def7..acac62c 100644
--- a/tests/setup-osx.sh
+++ b/tests/setup-osx.sh
@@ -6,6 +6,7 @@
 
 bash tests/cleanup.sh
 
+touch tests/temp/emptyfile.tmp
 gtruncate -s 1M tests/temp/smallfile.tmp
 gtruncate -s 2050M tests/temp/mediumfile.tmp
 gtruncate -s 4100M tests/temp/bigfile.tmp
diff --git a/tests/setup.cmd b/tests/setup.cmd
index 0be5556..3920450 100644
--- a/tests/setup.cmd
+++ b/tests/setup.cmd
@@ -1,5 +1,6 @@
 rem http://stackoverflow.com/a/986041/631369
 call tests\cleanup.cmd
+fsutil file createnew tests\temp\emptyfile.tmp 0
 fsutil file createnew tests\temp\smallfile.tmp 1048576
 fsutil file createnew tests\temp\mediumfile.tmp 2149580800
 fsutil file createnew tests\temp\bigfile.tmp 4299161600