diff --git a/forms/CurrencyField.php b/forms/CurrencyField.php
index aa3d7bfca..7a260b0e2 100755
--- a/forms/CurrencyField.php
+++ b/forms/CurrencyField.php
@@ -13,14 +13,14 @@ class CurrencyField extends TextField {
 	 */
 	function setValue($val) {
 		$value = ($val) ? $val : 0.00;
-		$this->value = '$' . number_format(ereg_replace('[^0-9.]', '', $value), 2);
+		$this->value = '$' . number_format((double)preg_replace('/[^0-9.\-]/', '', $value), 2);
 	}
 	/**
 	 * Overwrite the datavalue before saving to the db ;-)
 	 */
 	function dataValue() {
 		if($this->value){
-			return preg_replace('/[^0-9.]/',"", $this->value);
+			return preg_replace('/[^0-9.\-]/','', $this->value);
 		}else{
 			return 0.00;
 		}
@@ -54,7 +54,7 @@ Behaviour.register({
 			if(!el || !el.value) return true;
 			
 			var value = \$F(el);
-			if(value.length > 0 && !value.match(/^\s*\\\\$?(\d{1,3}(\,\d{3})*|(\d+))(\.\d{2})?\s*\$/)) {
+			if(value.length > 0 && !value.match(/^\s*(-?\\\$?|\\\$-?)?(\d{1,3}(\,\d{3})*|(\d+))(\.\d{2})?\s*\$/)) {
 				validationError(el,"$error","validation",false);
 				return false;
 			}
@@ -72,7 +72,7 @@ JS;
 	}
 
 	function validate($validator) {
-		if(!empty ($this->value) && !preg_match('/^\s*\$?(\d{1,3}(\,\d{3})*|(\d+))(\.\d{2})?\s*$/', $this->value)) {
+		if(!empty ($this->value) && !preg_match('/^\s*(\-?\$?|\$\-?)?(\d{1,3}(\,\d{3})*|(\d+))(\.\d{2})?\s*$/', $this->value)) {
 			$validator->validationError($this->name, _t('Form.VALIDCURRENCY', "Please enter a valid currency."), "validation", false);
 			return false;
 		}
diff --git a/tests/forms/CurrencyFieldTest.php b/tests/forms/CurrencyFieldTest.php
new file mode 100644
index 000000000..2a4f29a42
--- /dev/null
+++ b/tests/forms/CurrencyFieldTest.php
@@ -0,0 +1,106 @@
+<?php
+/**
+ * @package sapphire
+ * @subpackage tests
+ */
+class CurrencyFieldTest extends SapphireTest {
+
+	function testValidate() {
+		$f = new CurrencyField('TestField');
+		
+		$f->setValue('123.45');
+		$this->assertTrue(
+			$f->validate(new RequiredFields()),
+			'Validates positive decimals'
+		);
+		
+		$f->setValue('-123.45');
+		$this->assertTrue(
+			$f->validate(new RequiredFields()),
+			'Validates negative decimals'
+		);
+		
+		$f->setValue('$123.45');
+		$this->assertTrue(
+			$f->validate(new RequiredFields()),
+			'Validates positive decimals with sign'
+		);
+		
+		$f->setValue('-$123.45');
+		$this->assertTrue(
+			$f->validate(new RequiredFields()),
+			'Validates negative decimals with sign'
+		);
+		
+		$f->setValue('$-123.45');
+		$this->assertTrue(
+			$f->validate(new RequiredFields()),
+			'Validates negative decimals with sign'
+		);
+		
+		$f->setValue('324511434634');
+		$this->assertTrue(
+			$f->validate(new RequiredFields()),
+			'Validates large integers'
+		);
+	}
+	
+	function testSetValue() {
+		$f = new CurrencyField('TestField');
+		
+		$f->setValue('123.45');
+		$this->assertEquals(
+			$f->value, '$123.45',
+			'Prepends dollar sign to positive decimal'
+		);
+		
+		$f->setValue('-123.45');
+		$this->assertEquals(
+			$f->value, '$-123.45',
+			'Prepends dollar sign to negative decimal'
+		);
+		
+		$f->setValue('$1');
+		$this->assertEquals(
+			$f->value, '$1.00',
+			'Formats small value'
+		);
+		
+		$f->setValue('$2.5');
+		$this->assertEquals(
+			$f->value, '$2.50',
+			'Formats small value'
+		);
+		
+		$f->setValue('$2500000.13');
+		$this->assertEquals(
+			$f->value, '$2,500,000.13',
+			'Formats large value'
+		);
+		
+		$f->setValue('$2.50000013');
+		$this->assertEquals(
+			$f->value, '$2.50',
+			'Truncates long decimal portions'
+		);
+	}
+	
+	function testDataValue() {
+		$f = new CurrencyField('TestField');
+		
+		$f->setValue('$123.45');
+		$this->assertEquals(
+			$f->dataValue(), 123.45
+		);
+		
+		$f->setValue('-$123.45');
+		$this->assertEquals(
+			$f->dataValue(), -123.45
+		);
+		
+		$f->setValue('$-123.45');
+		$this->assertEquals(
+			$f->dataValue(), -123.45
+		);
+	}
+}